Object-oriented languages are a further level of development of procedural languages, the main concept of which is a set of program objects. Writing a program in a language is represented as a sequence of creating instances of objects and using their methods. These include the first languages Simula and SmallTalk, then C++, Java.

Declarative programming languages
In declarative programming, a specification of the solution to a problem is given, that is, a description of what the problem is and what the result is expected to be. Programs created with a declarative language do not contain variables or assignment operators. Declarative languages include SQL and HTML. Subspecies of declarative programming include functional and logical programming.

Functional programming languages
Functional languages are artificial intelligence languages. A program written in a functional language consists of a sequence of functions and expressions to be computed. The basic data structure is a linked list. Functional programming is fundamentally different from procedural programming. The main functional languages are Lisp, Miranda, Haskel. Logical programming languages Languages focused on solving problems without describing algorithms, languages of artificial intelligence. A representative of logical programming is Prolog, which is used to write the majority of expert systems.

Scripting languages (scripts).
Languages are object-oriented languages, used to write programs that are executed in a specific software environment. Program texts written in scripting languages can be included in the body of an Html document. The first scripts were Perl and Python, which were originally developed for the Unix operating system, and later there were versions of languages for Windows and Macintosh operating systems. To write programs in scripting language, it is necessary to know the procedures and functions of the system libraries.

Data-oriented languages
Languages are oriented to work with one particular type of data. For example, APL works with matrices and vectors, Snobol processes strings, SETL performs operations on sets. Languages for working with databases are especially developed: 3GL, PL/SQL, FoxPro.

Thus, looking at the classification of programming languages by category, we can conclude that the division is associated with the methods used in writing programs. These methods are designed to form the necessary functionality, which responds to the request to write a particular language.

A programming language oriented to a specific type of processor and taking into account its features is a low-level programming language. The operators of a low-level language are close to machine code and are oriented to the specific commands of the processor. Programming languages imitating natural languages, having enlarged commands oriented to solution of applied substantial tasks are called high-level languages.

This classification also defines the place of the language usage and further perspectives of its development. Association of languages by the method of their writing, allows you to better define the environment of their use, which greatly improves the quality of writing programs and allows you to maximize its use.

This classification allows for further consideration of the criteria for the selection of the environment and programming language.