Words are the building units of every book. Like books, programming languages have commands, variables, constants, ... which are building units of every software. Software languages are a set of commands which tells a computer what it needs to do. Software languages can be programming, structural and styling. As we said, books are written in many languages, so most common world programming languages are:

• PHP;
• Python;
• C;
• C++;
• JavaScript;
• Swift;
• Java; …

Programs like MS Word are made in the C programming language. Drupal CMS is made in PHP. When a programmer writes commands in a programming language, that is called coding. There are few ways of programming, but OOP and procedural are most common. Drupal is made in OOP way of programming. But all what we said now, refers to programming languages. But what are then markup and styling languages? We will base this article only on software languages used in Drupal.

Software languages used in Drupal CMS

For example, let's say there are two parts of human brain, part for programming and part for markup with styling. So, programming part of brain decide to write some wise sentence on paper. Then markup with styling part of the brain decides what color of pen will use, what kind of paper will use, will it write small caps or all caps. Markup and styling languages, making structure of look and design. When a coded programming language defines what it will do, it generates data to markup and styling languages how it will represent to the user. For example, a programming language tells a computer to display some image. Then markup with styling language decides how big will the image be, will there be shadow, which frame will be set and what color.

HTML

HyperText Markup Language or HTML can’t be defined as a programming language but structural or markup language. Design skeleton or design structure of all webpages is made in HTML. But HTML is just a skeleton with no larger designs like effects, shadows, animation… for that you need CSS. Otherwise, most text styling is credited to HTML, like bold, italic, justification, ... So, there are some tools for content writers what styles plain text. It is just text without any formatting. Plain text, is with no HTML tags and no special graphic display. Such type of text is suitable to be styled in WYSIWYG and then formatted for webpage. WYSIWYG is a tool for styling plain text, inserting images, links, ...

CSS

Cascading Style Sheets or CSS can’t be defined as programming language but styling language. While HTML is the skeleton of a website, CSS is the skin. Every website design is made in CSS. Larger designs like effects, shadows, animation… are defined in CSS. Cascading Style Sheets are also defining responsive designs.

Programming languages

JavaScript

JavaScript or JS is a frontend programming language. In detailed, JS is scripting language, what is a subcategory of programming language. JS is an inescapable part of frontend development and its commands can trigger animations, select, delete, arrange or move HTML objects, … But JavaScript is not suitable for backend development, except some versions like Node JS. Practically, every website uses JavaScript. JS can use some libraries like jQuery, Vue.js or Dojo.js which can help to make some actions with less coding. JavaScript is not Java, which is a totally different programming language.

PHP

Personal Home Page or Hypertext Preprocessor is a programming language founded 1994. It is backend language, and it powers about 80% of all websites! PHP 8 with minor advances is the newest version. From PHP 7 in 2014, this programming language gets crucial performance updates, today it's defined as faster programming language. PHP constructs Drupal from the beginning. From Drupal 8 PHP constructs CMS in Object-Oriented Programming (OOP), what is much better. Drupal's developers constantly improves PHP code and reduces deprecated code and bugs. A bug is an error in coding, so the program produces unexpected results because of it. Modules and core updates are often caused by bugs' existence and security improvement. Bugs can exist in all four mentioned languages.

Twig

Perhaps Twig is not a software language, but it behaves like one. It is template engine made by Symfony developers. From Drupal 8 it is main component of frontend theme system. Twig is a combination of HTML and PHP, so this engine behaves like markup and programming language. It accepts HTML tags and also PHP commands like some loops, the Twig sanitizing code and not allow unsafe functions to run. About Twig.