Actually what are the difference between all the programming language ? Does it meant c++ or else can do everything ? Either each programming language have its own specific function to do sth or what ?

Answer 1

First, programming languages are a way to be able to talk to a machine in a language understandable by a human. Technically, you can code machine instructions directly with 0s and 1s, but, well, this isn't exactly practical. So, at the very least we will use an assembly language. Assembly instructions can be directly translated (line by line) into machine instructions.

However, coding in assembly is still difficult, especially the management of the memory, and the code is still hard to read/understand. So languages with higher levels of abstraction have been developed, easing the process of writing programs, limiting errors, and providing things like if/then/else, for/while loops, OOP, etc. In some languages, the code is parsed and converted into a program by a compilator, in others it is interpreted on the fly by an interpreter.

Anyone can invent their own language and code their own compilator/interpreter for it. Popular ideas are taken by others, new programming paradigms are developed, languages evolve, yada yada. And here we are today, with a collection of programming languages developed by different people for different uses.

Often, the popular programming languages have different functions. For example:
html/css/javascript are for developing webpages
php is to serve dynamic webpages
mysql is for manipulating databases
perl is for text parsing
And then you have all-purpose languages, including script languages (python, ruby, etc.) for ease of use and portability, compiled languages (C/C++/C#, etc.) for speed (for pure speed, write directly in assembly), or even hybrid languages like Java which offer a good middle ground.

I would suggest you to learn at least Java, C/C++/C# (one of the three), and a script language like Python. Or if you are interested in web dev, learn html/css/javascript/php/mysql, you can even make programs for the desktop with those nowadays.

Answer 2

HTML - used for web page designing
CSS - used for adding styles to the web page
Java script - creates user interactions on a web page
PHP - creates dynamic web pages
C ,C++ ,Java are used for creating mobile and desktop applications
Each language that's created serves different purposes and has separate functionalities .