operating system

Operating System

An operating system is a program that acts as an interface between the user and the computer hardware and controls the execution of all kinds of programs.

The operating system is the most important program that runs on a computer. Every general-purpose computer must have an operating system to run other programs. Operating systems perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers.

For large systems, the operating system has even greater responsibilities and powers. It is like a traffic cop -- it makes sure that different programs and users running at the same time do not interfere with each other. The operating system is also responsible for security, ensuring that unauthorized users do not access the system.

An operating system, or "OS," is software that communicates with the hardware and allows other programs to run. It is comprised of system software, or the fundamental files your computer needs to boot up and function. Every desktop computer, tablet, and Smartphone includes an operating system that provides basic functionality for the device.

Common desktop operating systems include Windows, Mac OS X, and Linux. While each OS is different, they all provide a graphical user interface, or GUI, that includes a desktop and the ability to manage files and folders. They also allow you to install and run programs written for the operating system. While Windows and Linux can be installed on standard PC hardware, Mac OS X can only run on Macintosh computers. Therefore, the hardware you choose affects what operating system(s) you can run.

Mobile devices, such as tablets and Smartphone’s also include operating systems that provide a GUI and can run applications. Common mobile OSes include Android, iOS, and Windows Phone. These OSes are developed specifically for portable devices and therefore are designed around touchscreen input. While early mobile operating systems lacked many features found in desktop OSes, they now include advanced capabilities, such as the ability to run third-party apps and run multiple apps at once.

Since the operating system serves as a computer's fundamental user interface, it significantly affects how you interact with the device. Therefore, many users prefer to use a specific operating system. For example, one user may prefer to use a computer with Mac OS X instead of a Windows-based PC. Another user may prefer an Android-based Smartphone instead of an iPhone, which runs the iOS.

When software developers create applications, they must be write and compile them for a specific operating system. This is because each OS communicates with the hardware differently and has a specific application program interface, or API, that the programmer must use. While many popular programs are crossplatform, meaning they have been developed for multiple OSes, some are only available for a single operating system. Therefore, when choosing a computer, it is important to make sure the operating system supports the programs you want to run.

ERP

                                                                

ERP is an acronym for "Enterprise Resource Planning". An ERP attempts to integrate all departments and functions across a company onto a single computer system that can serve all those different department's particular needs.

E: Enterprise is a huge business Organisation.
R: Resources are Money, Material, Man power, Machinery, and Methods
P: Planning for optimal Utilization of resource for a huge business Organisation implementation

Enterprise resource planning software, or ERP, doesn’t live up to its acronym. Forget about planning—it doesn’t do much of that—and forget about resource, a throwaway term. But remember the enterprise part. This is ERP’s true ambition. It attempts to integrate all departments and functions across a company onto a single computer system that can serve all those different departments’ particular needs.
That is a tall order, building a single software program that serves the needs of people in finance as well as it does the people in human resources and in the warehouse. Each of those departments typically has its own computer system optimized for the particular ways that the department does its work. But ERP combines them all together into a single, integrated software program that runs off a single database so that the various departments can more easily share information and communicate with each other.
That integrated approach can have a tremendous payback if companies install the software correctly.
Take a customer order, for example. Typically, when a customer places an order, that order begins a mostly paper-based journey from in-basket to in-basket around the company, often being keyed and rekeyed into different departments’ computer systems along the way. All that lounging around in in-baskets causes delays and lost orders, and all the keying into different computer systems invites errors. Meanwhile, no one in the company truly knows what the status of the order is at any given point because there is no way for the finance department, for example, to get into the warehouse’s computer system to see whether the item has been shipped. "You’ll have to call the warehouse" is the familiar refrain heard by frustrated customers.
ERP vanquishes the old standalone computer systems in finance, HR, manufacturing and the warehouse, and replaces them with a single unified software program divided into software modules that roughly approximate the old standalone systems. Finance, manufacturing and the warehouse all still get their own software, except now the software is linked together so that someone in finance can look into the warehouse software to see if an order has been shipped. Most vendors’ ERP software is flexible enough that you can install some modules without buying the whole package. Many companies, for example, will just install an ERP finance or HR module and leave the rest of the functions for another day.

  Why ERP-

There are five major reasons why companies undertake ERP.

Ø  Integrate financial Information

Ø  Integrate Customer Order Information

Ø  Standardize and speed up manufacturing processes

Ø  Reduce inventory

Ø  Standardize HR information.

ERP is used for planning resources [Money, Material, Man power, Machinery and Methods] to get maximum profits with minimum Efforts.  For this, all the business functions and processes need to be atomised and integrated.   The common business functions of any large enterprise are-

                                                                                                                                 

 FICO -Financial Accounting & Controlling, HR -Human resources,

PP-Production planning, MM -Material Management, SD -Sales and distribution
PM -Plant Maintenance, QM -Quality Management, etc depending on the enterprise.

ERP Implementation -

No matter what type of business you're in, implementing an ERP solution is a critical project that must be taken seriously. From concerns about cost and demonstrating ROI, to practical considerations about who will manage the process at your company, ERP implementation efforts require commitment by a project team and support by business leaders to ensure success.
There's no getting around the fact that ERP deployment is a major undertaking, but the process doesn't have to be painful. With proper planning and execution, implementing an ERP system should be a smooth process and quickly improve efficiency across your business. Here are some critical ERP implementation best practices to consider when selecting and deploying a solution.

Select the Best ERP Implementation

Given the range of functions that ERP encompasses, it should come as no surprise that there are multiple types of ERP implementations. You can choose to build your own custom ERP and program it from the bottom up, though the cost and complexity of taking on such a huge project can make a do-it-yourself approach a poor one.
Or you can purchase on-premise ERP software and install it on your company's computers and servers. Before investing in an on-site ERP solution, however, consider this sobering fact: Two-thirds of mid-size businesses are running old versions of their ERP software. ¹Why the lag? Organizations often decide that the pain required to re-implement incremental releases is too great—especially since each upgrade means the business risks losing critical customizations and integrations. Keeping ERP technology current is key to maximizing its potential, so it's essential to choose a system deployment option that's easy to update and will preserve custom features.
There's a third alternative: a cloud-based ERP solution like NetSuite. Because the system is cloud-based and managed entirely off site by the ERP provider, a cloud-based solution means you don't have to make expensive upfront investments in IT hardware and servers, nor worry about dedicating significant personnel resources to managing it. In addition, cloud-based implementations are usually much faster and easier to deploy than on-site deployments, and maintenance is much easier since the cloud-based ERP provider is responsible for keeping the technology up to date. Most importantly, with cloud technology, product enhancements are painless—customizations and integrations automatically update with system upgrades—so you can always be assured that your business is running with the most advanced capability.

 Consensus around ERP Implementation

Getting buy-in from company executives means more than just getting a signature to approve investment in an ERP solution (though that is certainly important); it means educating leadership about what ERP implementation means for the company. More than just software, ERP technology can transform the business, an idea that executives must support before moving forward with any deployment effort. Frequent communication from executives about ERP implementation plans and changing processes are vital to helping build consensus—and even excitement—across your company.

Set Realistic Expectations for ERP Implementation

ERP software is powerful technology that can streamline processes, improve visibility, reduce costs, and completely change the way that your company does business—but it won't happen overnight. ERP solutions encompass many complex front- and back-office systems, from accounting and inventory management to ecommerce and CRM, which need to be integrated to create a seamless experience for end users.
This takes careful planning and time to execute. To accelerate the implementation process, make sure your project is scoped appropriately and consider working with an experienced, knowledgeable ERP expert. The average NetSuite customer is typically able to implement its ERP system within three months—much less than the on-premise ERP implementation industry average of a year and a half.

Focus on Staff Resources and  Project Management

Before starting any ERP implementation, make sure that your company has the staff resources in place to see the project through to completion. This may seem like an obvious point, but many companies begin deployment without resourcing it adequately, resulting in overworked, unhappy employees and a less-than-optimal installation.Identifying a dedicated project leader and a team for your ERP implementation will help ensure that the project goes smoothly. For ERP team members, consider reassigning or removing some of their normal job duties so they have enough time to concentrate on the task at hand. Identify a team leader with strong project management skills who can facilitate team communication, address any issues that may arise, and keep the implementation on schedule.
Keeping these best practices in mind will help you launch your deployment on the right track and keep it there throughout the entire process. Researching the best ERP implementation option for your business, building consensus around the effort, setting realistic expectations, and giving your staff the support they need—these steps take more time, but they result in a more effective ERP experience and a better-run business in the long term.

java script

 Java Script

What Is JavaScript?

An explanation of exactly what JavaScript is has to begin with Java. Java is a new kind of Web programming language developed by Sun Microsystems. A Java program, or applet, can be loaded by an HTML page and executed by the Java Interpreter, which is embedded into the browser.
Java is a complex language, similar to C++. Java is object-oriented and has a wide variety of capabilities; it's also a bit confusing and requires an extensive development cycle. That's where JavaScript comes in.
JavaScript is one of a new breed of Web languages called scripting languages. These are simple languages that can be used to add extra features to an otherwise dull and dreary Web page. While Java is intended for programmers, scripting languages make it easy for nonprogrammers to improve a Web page.
JavaScript was originally developed by Netscape Corporation for use in its browser, Netscape Navigator. It includes a convenient syntax, flexible variable types, and easy access to the browser's features. It can run on the browser without being compiled; the source code can be placed directly into a Web page.
You can program in JavaScript easily; no development tools or compilers are required. You can use the same editor you use to create HTML documents to create JavaScript, and it executes directly on the browser (currently, Netscape or Microsoft Internet Explorer).
JavaScript was originally called LiveScript, and was a proprietary feature of the Netscape browser. JavaScript has now been approved by Sun, the developer of Java, as a scripting language to complement Java. Support has also been announced by several other companies.
Although useful in working with Java, you'll find that JavaScript can be quite useful in its own right. It can work directly with HTML elements in a Web page, something Java can't handle. It is also simple to use, and you can do quite a bit with just a few JavaScript statements. You'll see examples of the power of JavaScript throughout this guide.

History of JavaScript

As mentioned before, the history of JavaScript begins with Java. Java was originally developed by Sun Microsystems for use in "real-time embedded systems"-in other words, consumer electronics. Java has now become the de facto standard for advanced Internet programming, but you may still see it running your cellular phone someday.
Java was designed to operate on a virtual machine-a piece of software that interprets the Java code and acts on it as if it were a computer in itself. The virtual machine was designed to be simple so it could be implemented easily in a device. This is what makes it easy to implement in Web browsers.
Java was originally supported only by HotJava, an experimental Web browser developed by Sun for that purpose. Recognizing its potential, Netscape integrated it into its Web browser, Netscape Navigator. Because Navigator is the most popular browser, this greatly increased the publicity for Java.
In 1995, Java became the hottest new buzzword for the Internet, but few people actually knew how to program it. Netscape Communications recognized the need for a simple, clear language for Web pages and introduced LiveScript, the first of the Web scripting languages.
LiveScript had a syntax based on Java, but was more concise and easier to learn. It was also a directly interpreted language rather than a compiled language like Java. Netscape built LiveScript into the beta versions of Netscape Navigator. Support for LiveScript began with version 2.0b1, released in June 1995.
Later in 1995, Netscape reached an agreement with Sun. Sun also recognized that a simple scripting language was a good idea, so they officially endorsed LiveScript. Thus, the connection with Java became official, and the name changed to the one you're familiar with: JavaScript.
At this writing, JavaScript is still being developed and continues to improve. Netscape's support for JavaScript is expected to be finalized by the end of 1996, and other companies-most notably, Microsoft-are rushing to release competing products. Microsoft Internet Explorer (MSIE) 3.0, currently in beta, supports basic JavaScript, along with Microsoft's answer to JavaScript, VBScript.

JavaScript Versus Java

The process of writing a Java applet can be complicated-writing the source code, compiling, and making the applet available on the server. JavaScript provides a much simpler alternative for small projects. The JavaScript source code is interpreted directly by the browser. The source can either be included directly within an HTML page or referenced in a separate file.
Although JavaScript doesn't really have any features that eclipse Java, it adds some conveniences, simplifies programming, and provides better integration with the browser. The key differences include the following (explained in the following sections):

• JavaScript can be combined directly with HTML.
• The JavaScript language structure is simpler than that of Java.
• The JavaScript interpreter is built into a Web browser.
• JavaScript is supported on more platforms than Java.

Combining JavaScript with HTML

Java applets are compiled and stored on the server as byte codes, but JavaScript programs are simple ASCII text files. You can keep them as separate files or include the JavaScript functions within an HTML page.
The <SCRIPT> tag, an extension of HTML supported by Netscape, enables you to include one or more JavaScript functions in the page. Example 1.1 is a very small JavaScript script embedded directly within HTML. You take a more detailed look at the syntax of these tags later in this chapter.

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Example 1.1.  A simple JavaScript program within an HTML document.
<HTML><HEAD> <TITLE>Simple JavaScript Example </TITLE> </HEAD> <BODY> HTML Text goes here. <SCRIPT LANGUAGE="JavaScript"> document.write("Here is  output.") </SCRIPT> </BODY></HTML>

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An alternate option called an event handler enables you to specify a JavaScript action that will be performed when an event occurs. For example, a button on the page might have an action performed when it is pressed. This provides a more dynamic method of accessing JavaScript.
Instead of the <SCRIPT> tag, an event handler is added as an attribute to an HTML tag. As an example, the following HTML code defines a link with an event handler: <A HREF="www.netscape.com" onClick="alert('This will take you to Netscape's home page.');">
In this case, the name of the event is onClick. This particular event happens when the user clicks on the link. The JavaScript code to perform when the link is clicked is enclosed within double quotation marks. 

Simplified Language Structure

The limitations of JavaScript also make it much easier for the programmer. The syntax of the JavaScript language is more relaxed than that of Java, and variables (names used to store values) are easier to use. Here are the specifics:

• The JavaScript language is interpreted rather than compiled. Changing a script is as simple as changing an HTML page.
• Rather than creating objects and classes, you can do quite a bit by simply accessing existing objects in JavaScript.
• Variables are loosely typed: You do not need to declare variables before their use, and most conversions (such as numeric to string) are handled automatically.
• Event handlers enable a JavaScript function to execute whenever an action is performed on part of the HTML document. For example, a form's input field can be checked for certain values whenever it is modified.

Web Browser Integration

JavaScript is an object-oriented language. This simply means that it can use objects. An object is a more complicated version of a variable. It can store multiple values and can also include actual JavaScript code. You can create your own objects to represent just about anything.
JavaScript also includes objects that enable you to access features of the browser directly. These objects represent actual elements of the browser and the Web page, such as windows, documents, frames, forms, links, and anchors.
You can access information about the links, anchors, and form elements in the current page. You can also control the browser with JavaScript. For example, it's possible to include a "back" button on your page that will send the user back to the previous page-just like the browser's back-arrow button.
Of course, when I say "browser" here, I'm talking about browsers that support JavaScript. Netscape Navigator began supporting it in version 2.0b1, and at this writing, version 3.0b6 is the latest version. It will also be supported by Microsoft Internet Explorer.