Lets take a look at each of these types of software in more detail.

Application Software
The term "Application Software" refers to a category of programs. Remember we said earlier software is a set of programs (stored sets of instructions) that we purchase or write to perform specific tasks.

Application software is used to accomplish specific tasks for the user.  Application software usually falls into several categories.

• Word Processing Software - gives you and your computer the capability of producing letters and other documents in a wide range of formats. (Example -WordStar, WordPerfect, Microsoft Word)

• Database Management Software - gives you and your computer the capability to accumulate and maintain large amounts of data such as lists of names and address, Inventory lists, and etc. (Example - dBase III and IV, Microsoft's Acess, and etc.)

• Spreadsheets Software - gives you and your computer the capability to keep track of business transactions, household budgets, etc. (Example - Lotus 123, Microsoft Excel)

• Integrated Software - combines two or more software programs into one integrated application. Integrated packages have two main advantages:
  • The user interface is the same in all areas of the package. This makes the software easer to learn.

  • Data can usually be transferred from on portion of the package to another.

  • Disadvantages include the fact that the individual parts of the software can be less powerful than software written for a specific purpose. Also integrated packages require more memory to run.

• Utility Software - Utility software is usually designed to perform a single specific function. For example, a program that only copies all files on your hard disk is a utility program. Utility software packages can be purchased separately or can sometimes come packaged with other application software. For example, the latest version of MS-DOS is packaged with some of the following utilities:
  • Defrag- Defrag is a scaled down version of the Norton Speed Disk. Files are written to a hard disk in units called clusters. Clusters can usually hold from 2000 to 8000 characters depending on the capacity of the hard drive.
    • When you first create and save a file, DOS often finds enough unused clusters in a row to write the complete file on the disk without a break.

    • As you add to a file or save it repeatedly over time, the next cluster on the disk might be used by another file. A file becomes fragmented when DOS must split the file across several cluster that are not in line.

    • As you work with files - creating them, deleting them, or copying them -- the file fragmentation on the disk increases.

    • Over time you computer can slow down as it waits for DOS to find the pieces of the file you want to work on. Defrag, defragments by placing all files in a sequential order (using clusters in line for the file).

  • Scandisk - Scandisk checks the disk for errors in the File Allocation Table (FAT) which contains the names and loctions of all of the files and programs on your computer.

  • Undelete - Sometimes we accidentally delete a file we did not want to. Undelete allows us to retrieve that file.

  • MSD - Microsoft System Diagnostic (MSD) takes a snapshot of your system hardware and memory configurations and displays the data on an easy to read screen. This program is useful for gathering data during a trouble-shooting sesson, or for just printing out a record of your systems configuration.

  • Desktop Utilities - Other types of utility programs exist to help us manage our desktop. As an example, in Microsoft Windows 95, programs exist to give you a computerized desk calendar, calculator, phone directory, spell checker, grammar checker, or notepad.

• Desktop Publishing - Desktop publishing software is used to produce documents that contain both text and graphics. These programs are used to produce layouts for newspapers, books, and catalogs, etc. A good example is handouts produced for training classes. They are usually produced with a desktop publishing program.

• Presentation Software - This type software is used to create graphics presentations and slide shows. An example of programs used is, Harvard Graphics, Powerpoint, or Freelance Graphics presentations. Some of this course was produced by using presentation software.
  • Note: Please note that each computer must have its own original copy of every software package (that is on that computer) for the computer to be legal. Everyone should be aware of where their original software is located and make sure the software on their PC is legal.

Operating Systems (OS)
All computers require a operating system. Throughout the years several major operating systems jave entered the market place. Some of the Operating Systems you may have heard about are:

• Bell Laboratories UNIX You can view a brief history of UNIX By Charles Severance at this link.

• Microsofts's MS\DOS
• Microsoft's Windows operating systems.  You can view a brief history Windows operating system at this link.

  Therefore, a operating system:

  • Links Hardware
  • Enables File Management
  • Provides an interface between you and your computer
  • Controls devices like Printers, Keyboards, Floppy disks, and Monitors.

OS Command Processing
When you start up your computer each morning a program called a command processor is loaded into memory. This command processor transulates your commands entered at the keyboard into a language the computer understands. This works in much the same way a language interpreter translates between two languages.

When the command processor is in control of the PC, it displays a command prompt. When Microsofts MS-DOS is used as the OS, the command prompt looks very much like the one shown below. When the computer displays the prompt on your screen it is telling you that it is ready for your commands.

C:\>

OS Services
When an application program is running, the OS provides services to the program. Some of the most important of these are the input, or output services.

For example, if you are using Wordstar (application program) and want to retrieve a file you have stored on the hard disk -- these OS services make it possible. As part of its services, the OS also manages all of the files that are stored on a hard disk or floppy disk.

To the OS, each document, spreadsheet, database, or program is called a file. DOS makes no distinction between them -- it manages all of them in the same way.

OS commands
In addition to the OS services, the operating system provides commands you can use directly from the command prompt.

Most of them let you manage the files and directories on a disk. Some of the more common commands used in MS-DOS areshown at the right.

Typing A Command
Learning a OS is similar to learning a new language. You have to communicate by using words that the OS understands. The OS then takes these words or commands and translates them into a language that the physical components of the machine can understand. The way you use language is called syntax. Syntax is the proper format of a spoken language or typed command.

Just as with a spoken language, If you don't get the grammer correct, your will not be understood and therefore will not be able to communicate.

As you work through the exercises in this course, be careful to type the command (and any spaces) as they appear. If the command doesn't work as discussed, try typing the command again.

Case doesn't matter when you type a command. You can type the command in upper- or lowercase letters. DOS reads COPY, copy, and Copy as the same command.

If you make a mistake when typing, you can press the "Backspace" key to delete characters before you press the "Enter" key.

OS commands and the particular syntax involved with each one will be discussed in the following sections as we discuss in detail many commonly used commands.

Taking Care Of Your Software
You should take care of your software disks and CDs the same way you would take care of audio or video cassettes.

• Don't leave them in extreme heat.
• Don't spill anything on them.
• Don't open the metal shutter on the 3-1/2 disks.
• Keep them away from magnets.

Keep in mind that all electrical equipment puts out a magnetic field. This means the telephone, the electric pencil sharpener, and even the personal computer itself. Of course, you don't have to keep your phone in a desk drawer--just don't keep floppy disks near the phone.

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