WordPress is a free and open-source content management system that allows users to build beautiful websites and blogs. It has a large community of users, contributors, and developers who create themes and plugins to extend its functionality. To use WordPress, you need a domain name, web hosting with PHP and MySQL support, and to install WordPress files either through an automatic installer or manually by uploading and configuring files and databases. Popular plugins add features like contact forms, social sharing buttons, image galleries, backups, and performance optimizations.