A content management system (or CMS) is a system or the capability to manage and track the location of, and relationships among, a firm's content at an element level in a repository. High-end content management systems apply workflows, and enable the use and reuse of content and content collections. Content management systems can manage entire binary files (documents), components of files, or XML/SGML data.

CMS facilitates the organization, control, and publication of a large body of documents and other content, such as images and multimedia resources. A CMS often facilitates the collaborative creation of documents. A web content management system is a content management system with additional features to ease the tasks required to publish web content to web sites.

Web content management systems are often used for storing, controlling, versioning, and publishing industry-specific documentation such as news articles, operators' manuals, technical manuals, sales guides, and marketing brochures. A content management system may support the following features:

• Import and creation of documents and multimedia material
• Identification of all key users and their content management roles
• The ability to assign roles and responsibilities to different content categories or types.
• Definition of the content workflow tasks, often coupled with event messaging so that content managers are alerted to changes in content.
• The ability to track and manage multiple versions of a single instance of content.
• The ability to publish the content to a repository to support access to the content. Increasingly, the repository is an inherent part of the system, and incorporates enterprise search and retrieval.
• Some content management systems allow the textual aspect of content to be separated to some extent from formatting. For example the CMS may automatically set default colour, fonts, or layout.

The term Content Management System was originally used for website publishing and management systems. Early content management systems were developed internally at organizations which were doing a lot of web publishing, such as on-line magazines, newspapers, and corporate newsletters. In 1995, CNET spun out its internal web document management and publication system into a separate company called Vignette, which opened up the market for commercial content management systems.

As markets evolved, the scope of products promoted as content management systems greatly broadened, fragmenting the meaning of the term. Wiki systems and web-based groupware are often described as content management systems, in contrast to the original website publishing management system definition.