WordPress is a website builder and content management system. It is an open source software that anyone can use to make any kind of website imaginable.
It started out as a blogging platform in 2003 but soon transformed into a CMS and later a full-fledged website building platform. Today it powers more than 38% of all websites on the internet.
WordPress users may install and switch among different themes. Themes allow users to change the look and functionality of a WordPress website without altering the core code or site content. Every WordPress website requires at least one theme to be present and every theme should be designed using WordPress standards with structured PHP, valid HTML (HyperText Markup Language), and Cascading Style Sheets (CSS).