HTML / HTML5
HTML5 is a markup language used for structuring and presenting content for the World Wide Web and a core technology of the internet. It is the fifth revision of the HTML standard. Its core aims have been to improve the language with support for the latest multimedia while keeping it easily readable by humans and consistently understood by computers and devices.
CSS (Cascading Style Sheets)
Cascading style sheets (CSS) is a style sheet language used for describing the look and formatting of a document written in a markup language. It’s most common use is to style web pages and interfaces written in HTML.
CMS (Content Management System)
A content management system (CMS) is a computer program that allows publishing, editing and modifying content as well as maintenance from a central interface. CMSs are often used to run websites containing blogs, news, and shopping. Many corporate and marketing websites use CMSs. CMSs typically aim to avoid the need for hand coding but may support it for specific elements or entire pages.
An individual element that can be adjusted in the style sheet, eg. fonts, margins, padding and colour.