A headless CMS is a backend content management system that separates the content repository from the frontend user interface layer, allowing it to deliver content to multiple "heads" such as mobile apps, chatbots, and voice-activated digital assistants. This approach offers several benefits including improved developer productivity, faster site updates, better scalability, improved security, and easier internationalization and localization. Headless CMSes enable teams to select best-of-breed tools that work for their needs, allowing content creators, content editors, development teams, and end users to focus on their area of expertise without being constrained by a monolithic platform. With the ability to serve content to multiple heads, headless CMSes can deliver omnichannel content and improve site performance, Core Web Vitals, and SEO rankings. Popular headless CMS platforms include Contentful, Strapi, Ghost, Forestry, Sanity, and Headless WordPress, each offering unique features and customization options for building a Jamstack project.