WordPress is a popular open-source content management system (CMS) used for building websites, including blogs. It is widely used for its ease of use, flexibility, and customization capabilities, making it a great choice for bloggers who want to create and manage their online presence. WordPress offers a range of templates and plugins to help users create a visually appealing and functional blog, with features such as the ability to easily add text, images, and media, manage comments, categorize content, and much more. Additionally, it's free and has a large online community, providing users with access to support and resources to help them get the most out of their blog.