WordPress.org is an open source content management system (CMS) that allows users to download and use the software for free, with full control over their website's customization. In contrast, WordPress.com is a commercial service that offers a streamlined way to set up a website using a modified version of the WordPress CMS, but with less control over customization and a focus on ease of use. The two services are managed by different companies, one being Automattic and the other being the nonprofit WordPress Foundation. While both options have their pros and cons, users should consider their needs and choose between self-hosting using WordPress.org or using WordPress.com for its ease of use and support.