The Full Form of CWD is‍ Comment When Done.

Commenting involves placing Human Readable Descriptions inside of computer programs detailing what the Code is doing. Proper use of commenting can make code maintenance much easier, as well as helping make finding bugs faster. Further, commenting is very important when writing functions that other people will use. Remember, well documented code is as important as correctly working code.

All programs should be commented in such a manner as to easily describe (in English) the purpose of the code and any algorithms used to accomplish the purpose. A user should be able to utilize a previously written program (or function) without ever having to look at the code, simply by reading the comments.

Commenting is the “art” of describing what your program is going to do in “high level” English statements. Commenting is best done before actually writing the code for your program.

Comments are specially marked lines of text in the program that are not evaluated. There are usually two syntactic ways to comment. The first is called a single line comment and, as implied, only applies to a single line in the “source code” (the program). The second is called a Block comment and refers usually refers to a paragraph of text. A block comment has a start symbol and an end symbol and everything between is ignored by the computer.