Give the units that the variavle is in in the comments. Keep code modules under 10 pages of code. If the code changes, make sure that the comments reflect the change. There are many different programming languages available on computers today. Most languages have specific areas of application that they are best suited for.
Most current languages have specific areas of successful application.
It would be impossible to list all computer languages, anyone can create their own. Nicklaus Wirth created Pascal as an instructional programming language. Good for writing with money, inventory, and data base applications. Very large base of installed programs. C See Kernighan and Richie's .