The key item is the compiler. The compiler takes the programming language and converts it into a language and sequences that the computer can understand. The other item is the library. It is a set of commands that the compiler can understand and can translate into the machine language. The programming language is what you use to create your processes. Most of them are directly related to logic sequences and storing and retrieving of data. You write the commands in the programming language, run it through the compiler which converts it to machine code and then have an executable program.