Let's start with the very first programming languages. They appeared in the distant 50-ies of the last century. Then they are only allowed to perform the most simple commands. For example, such programming languages allow to add and multiply numbers, for this was written custom code. And do these languages need to convert the code human-readable in the clear for the CPU text. Because the CPU works only with binary code, such code for the CPU can be just a set of numbers: 0101000001. To convert programming language into machine understandable code, use the compiler or interpreter. For example, to convert a C++ compiler is used, and to work with the Python language we need a special interpreter.
For a better understanding of why programming languages are and what they are useless, it is necessary to cite as an example the Internet. Every day you visit dozens of different interesting sites. In order for these sites to function properly, it is essential this website to create. Most websites are created using HTML markup, but it is necessary to understand that HTML is not a programming language. It is only necessary to create a simple website. To create a good functional website should also you to learn Perl or PHP, it's already a full-fledged programming languages.
There are two main groups of programming languages, the first group is low-level, and the second group is a high — level. The language of the first type is the most close to the native code. It is believed that they are the hardest to program. But in high-level programming language code more similar to human text.
The languages are very different, a lot of them. However, popular little. Popular language is C++ and there are C# (C "sharp"). This language was developed by the company MicroSoft. There are still Delphi, is an enhanced Pascal. I'm sure many people have studied Pascal in school. Delphi was developed by Borland, and the company has created a development environment Borland Delphi.
Most people believe that a computer is only a laptop or system unit, and maybe a tablet with a phone, but it is not so. Computers surround you everywhere, even regular TV is already a computer terminal in the Bank is also a computer. Even modern air conditioners are computers. And that the appliances all functioned, and there are millions of programmers worldwide developing program code to each device.