How are formal semantics used in programming?

What are the programming languages and what are they used for?

• If layman's terms means analogies, omnipresent in the famous: , than that is not what I'm looking for. I want to know literally, what each programming language is used for, and why its best used in that way, if possible. If CSS and HTML5 are the norm for front-end development, I want to know precisely that. Bullet-point format please. Thanks in advance.

• Answer:

  So in terms of web development, you will usually need a combination of the following technologies (not necessarily programming languages, as you will see): HTML: a markup language that specifies the structure of a site. CSS: a stylesheet language that specifies the presentation of a site. JavaScript: a dynamic programming language that is universally accepted as the client-side programming language.  People use it to create what we call "dynamic websites", meaning websites with animations.  There are more complex usages of JavaScript in the client side but I won't go in depth here. The three things above are what consist of the client side, or front-end, of a web application.  It's important to keep in mind that HTML and CSS are not programming languages.  For what a programming language really is, check out http://en.wikipedia.org/wiki/Programming_language. Server side, or backend is vastly more complex.  Usually people use some kind of dynamic programming languages like PHP, Python, and Ruby as server-side scripting languages, but static-typing languages like Java and C# are also used.  Almost always, you will also want to use some kind of web development frameworks like Ruby on Rails, and some database software like MySQL.  For computation-intensive web applications, you will also want to write part of your application in lower-level programming languages like C. If you want to start learning web development, I recommend this online course: https://www.udacity.com/course/cs253 Good luck!