This is the process of writing instruction that the computer is able to understand. To program means to create a program, a program is also called software.
To program usually you use programming languages, there are many many programming languages used in different ways and for different purposes.
Programming languages are necessary for programmers to program. Programming languages have been around for over 60 years, but the first programming language was written in the 1940s. There are many different types of programming languages for different purposes; it really depends on what you want to do with it.