WordPress is a popular content management system (CMS) used for website development. It is an open-source platform, which means it is free to use and customize. WordPress is known for its ease of use, making it a popular choice for both small and large websites, including blogs, portfolios, and e-commerce sites. The platform is built using PHP and MySQL, and it uses templates called themes to control the layout and design of a website. WordPress also has a large library of plugins, which are small pieces of software that add specific functionality to a website, such as contact forms, social media integration, and SEO optimization. Developers can create custom themes and plugins to extend the functionality of a WordPress site, making it a highly flexible and customizable platform for website development.