A programming language is a convention adopted for the implementation of a communication between programmer and computer. Computer programming languages used are very similar to natural languages.
The communication languages can be classified in several ways. Below there is a list with the most important classes of languages, description that covers all existing languages.
Languages of low or high level
The “level” of a language is appreciated by the position it occupies on the ladder that makes it recognized by the microprocessor (machine language) and by the programmer’s natural language (Italian, Spanish, English, Dutch). A low level language handles hardware-level elements, physical, such as register, microprocessor, memory location, port of entry / exit and so on. A high level language allows the machine and user to manipulate high or very close to natural language concepts, concepts of logic level, such as data collection, operation name (to sort, write statements, open programs), variables, constants (similar in meaning to those of mathematics).
With a high level language, the programmer is more easily understood by the computer. Sometimes a single limited written program in such language can sum up hundreds of lines written in machine language program. So in terms of reducing the time to build a program using the operational safety (no programming errors) is preferred creating a high-level language (high or very high). However, as the language has a higher level designed to help its implementation, it will be slower than a program that performes the same operations but is written in a low level language.
Another essential difference between the two types of languages is the portability of being able to transfer programs to another type of machine than the one where they were built. From this point of view is the low level programs and languages are non-portable, because they are specific to the microprocessor. The programs conducted on a type of machine must be completely rewritten for the new type of machine, using a new set of instructions, which usually differ greatly. Things are different when the programs designed by a high-level languages, because they are detached from the machine. From such a computer program, an interposed compiler (or interpreter) solves the file-source transformation.
Procedural language and non-procedural languages is the other classification of which we discuss today. The two types of languages, procedural and non-procedural, are distinguished by the level of organization (structure) of a program. Non-procedural languages are designed to think at an instruction-level program, while the procedural require the programmer to develop programs to maintain a certain level of “thinking”. In a procedural language (languages are called structures), the programs are written instruction by instruction, but they are organized into logical blocks (groups of instructions) which create a clearly defined action. Generally a block has one entry point and a point exit.
A procedural language offers the possibility of using a high level design of a program and leads to the development of coherent programs which are protected from errors. By contrast, non-procedural language programmers often lead to uncontrollable programs, especially for large programs. Non-procedural languages are still preferred by some users due to their very short instructions and the possibility of learn and of use.
From the viewpoint of the applicability of a object-oriented language, they can be designed for a specific problem or any kind of problem. They are general purpose languages or in other words, untargeted on a problem. Oriented languages have a high degree of specificity on the non-oriented languages and there is a general framework that allows the user to introduce the concepts and the desired processing. So the essential difference between the two types of languages constitutes in a conceptual level which is defined by the programmer. The specialist already has full support. Thus the programmer can concentrate on the whole problem, while a non-specialist programmer can solve a lower level of a certain problem.
