When you have finished this project, you will be able to:
	describe internal documentation
	explain why internal documentation is necessary
	describe external documentation
	explain why external documentation is necessary

• internal documentation
• external documentation

Internal documentation are comments created within the program by the programmer. Internal documentation is used to provide information about the program. Generally, this type of documentation is called a comment, and explains the purpose of a particular line of code or why the programmer used a particular procedure. An example of internal documentation is shown below:

Note that the comments use a single quotation mark (') ahead of them, and that they appear in green. When the programmer types the single quotation mark, the program knows that what follows in the rest of the line is a comment and colours it green to make is easy to differentiate from the rest of the code.

Internal documentation is important because it provides information to programmers who may not be familiar with a particular program. Because there are many ways to solve a programming problem it is a courtesy to other programmers to explain why a specific procedure was used. In addition, internal documentation reminds a programmer why particular code was written - even if it is months since the programmer saw the code last.

External documentation is usually a printed manual about the program, how it works, how to install it, or how to use it (user documentation). Sometimes external documentation is provided as a word processing document on the program disk, or as a manual for a user to read. If you have ever installed any software, you might recall seeing a file called readme. A readme file is a type of external documentation. User manuals and installation manuals are also types of printed external documentation:

You will be creating both internal and external documentation for your programs as you work through the projects for this course. Internal documentation will consist of making comments as you write your program code. This will be referred to as pseudo-code, which you will learn about in another project. Later in this course, you will create a User Manual for your programs.