What a project holds
A Meridian project stores the editing document, library references, sequences, and their settings. The .meridian file is not the same thing as an exported movie, and saving it does not automatically copy every referenced media file into that document.
A sequence is one editable timeline. Use separate sequences for distinct cuts, deliverables, or experiments that belong to the same project.
Create an alternate edit
Open Timeline → Sequences to create, duplicate, or rename a sequence. Duplicate a sequence before a substantial alternate edit so the original remains easy to return to. Give versions names that identify the purpose, such as “Interview — short cut,” rather than relying only on numbers.
Select the intended sequence before editing, generating captions, or configuring delivery. Confirm its name in the viewer and timeline.
Move a project safely
A project that opens on your Mac may still depend on files elsewhere. Before moving it to another drive or machine, use Collect Media into a Project Folder and check the collected result. Keep the original working folder until the moved project opens with its sources online.