Camtasia for Mac can save projects as standalone or referenced.
Standalone projects have media (screen recordings, sounds, still images, imported video) copied inside the .cmproj project, which is a special type of file called a Finder package. Referenced projects have the media stored elsewhere on the hard drive and the project simply points to those media files.
This article explains where original recording files are saved.
If you need to move projects from one computer to another, save as standalone so your media moves with the project. We recommend saving all projects and media files on a local hard drive, not network or cloud storage. We also recommend not moving or renaming any referenced media files as it can make the associated projects fail.