The FCP file extension is primarily associated with project files created by Apple's professional non-linear video editing software, Final Cut Pro. An FCP file is not a video file itself; rather, it acts as a container or a database that stores all the metadata, editing decisions, timeline arrangements, transitions, effects, and references to the source media files used within a project. When a user opens an FCP file, the software reconstructs the editing environment, allowing the editor to continue working exactly where they left off. Because these files rely on external media assets, they are relatively small in size. If the source media files are moved or deleted, the FCP project will show 'media offline' errors, as the file only contains pointers to the original footage rather than the footage itself. It is a proprietary format designed specifically for the Apple ecosystem, ensuring deep integration with macOS hardware and software workflows.