Bots on Wheels FRC 4290 Programming Documentation.
Methods (which are also called functions), are used to define and organize reusable code. They can be passed parameters (such as numbers, text, etc.), and are one of the fundamental building blocks for code in almost all programming languages.
Methods can be declared with values, if they are declared with a value, those values must be returned by the method.
Predefined methods are methods that have been declared inside of the standard Java classes and libraries. There are many different predefined methods, many of which you will use on a day-to-day basis. An example of one that is used a lot is the print line method, which will be explained here: Java Variables Print (W3 Schools).
The following article(s) explain methods: