I suppose what he really meant was if you save your project organized as a package or a folder.
I strongly recommend a folder.
A package means that there's only one file that represents your project, and that you can place media files such as audio files referenced by the project inside that package. So it's really a folder since you can put files inside, but it looks like a file in the Finder, and when you double-click it, it opens in Logic Pro, behaving like a file.
A folder means a Finder folder, and inside the folder you place your Logic Project file, along with other folders containing media files: an audio files folder, a sampler instruments folder, a samples folder, a bounced files folder, etc.