The work describes research and specification of basic paradigms of programming. The author analyzes and compares special features of programming languages of different levels, from Assembler to multi-paradigm programming languages. A functional models to comparative description of implementation semantics of basic paradigms is proposed. The author proposes a scheme of describing and defining paradigm features of a programming languages. The approach is illustrated with fragments of programming languages of different levels, which belong to machine-oriented, system, imperative, object-oriented, and productive programming.