Software

Software is the written computer "code" that contains instructions to enable the hardware to function and to do useful things. Without software, a computer would basically just be a collection of parts.

Software can be divided into many different categories, but the two most basic classifications are Operating Systems and Applications.

Operating Systems

A computer's operating system ( or OS, for short) serves several vital functions, the most basic of which is keeping track of and managing the computer's hardware. The OS operates in a very intimate relationship with the computer's hardware and, along with the BIOS, manages communication between all of the devices in and attached to the computer. It knows every device, how to address it, what software drivers it needs, and how it communicates with other hardware or with software.

The OS also provides a common platform with standardized interfaces for application programs. Most applications share similar needs, such as the need to print documents, for example. The operating system provides a way for many different programs to print to the same printer, without each program having to have its own printing subroutine.

The OS also controls communication between programs. This enables programs to share data, and allows users to do things like copy text from a web page into a word processor, just as an example.

Finally, the OS provides a user interface, which is how the user interacts with the computer. It includes routines to accept input from the keyboard, mouse, and other input devices, as well as to send data to the monitor, speakers, or other output devices.

The three most common operating systems for desktop computers are Windows, MacIntosh, and Linux. The three are not compatible, although there are programs called emulators that allow some (but not all) applications written for one application to run on another, with varying degrees of efficiency.

Applications

Applications are programs that enable a computer to perform useful tasks. There are many thousands of applications to do all manner of things. Some of the most common are:

• Word processors, which allow users to write letters and other documents.
• Spreadsheets, which provide ways to manipulate numeric data (such as financial records).
• Databases, which keep track of information of any conceivable kind and allow fast and efficient searching and retrieval of that information.
• Games.
• Multimedia applications to play and manipulate music and video.
• Graphics applications to create and modify pictures and other visual documents.

Applications are often bundled into suites that include several different programs written by the same publisher, and often allow various components of the suite to be used together to create and modify the same document. For example, a word processor may be bundled with an image editor that allows you to edit photographs that you want to place on a text document, without ever leaving the word processing program.

How Do I Get Software?

Software may be purchased on media (such as a CD-ROM), or it may be downloaded over the Internet. When you download software, you save a file from a remote computer to your computer over your Internet connection. You save the file in a convenient location, and then install it once it has finished downloading. You can find some free downloads for Windows computers here.

No matter how you get it, software must be designed for the particular operating system that you will be using. For example, if you are using a Windows XP computer, you must use software that is compatible with Windows XP. Software designed for older versions of Windows might work, but then again, it might not.

Information about what operating systems software will work with can usually be found on the box or package that the software comes in, or on the software publishers's Web site.