The Fundamental Concepts About Object-Oriented Programming

Ancient programming languages, such as C, Basic, or COBOL, followed a procedural style. The programs written in these languages consisted of a series of instructions, one after the other, that were executed step by step. To "enclose" functionality and be able to reuse it, they defined procedures (also called subroutines or functions). Still, global data was used, and it was tough to isolate specific data from each other. Thus, we could say that these types of languages focused more on logic than on data.