A term used to describe a set of objects at a specific version in rational ClearCase. A baseline is used as a foundation for branches, builds and releases.
Not all the objects in a baseline have to be at the same version. For example, the UI code in a project may be at version 1.1.2, while the database code is at 1.1.7 because it has had many bugfixes applied to it. If the UI and database code has been tested together and found to be stable, they may both be used together in a baseline for future work or release.