A vocabulary and set of grammatical rules for instructing a computer to perform specific tasks. High-level programming languages, while simple compared to human languages, are more complex than the languages the computer actually understands, called machine languages . Each different type of CPU has its own unique machine language. Lying between machine languages and high-level languages are languages called assembly languages . Assembly languages are similar to machine languages, but they are much easier to program in because they allow a programmer to substitute names for numbers.
Machine languages consist of numbers only.
4GLs are far removed from machine languages and represent the class of computer languages closest to human languages. Regardless of what language you use, you eventually need to convert your program into machine language so that the computer can understand it. The question of which language is best is one that consumes a lot of time and energy among computer professionals. Every language has its strengths and weaknesses. Pascal is very good for writing well-structured and readable programs, but it is not as flexible as the C programming language.