How do I close a project?

I am a rank beginner… so probably this is just my ignorance, but how do I close a project? The File->Close menu item seems to be always greyed out.

You can’t have Unity opened without having a project running. Kind of like how you cannot run Word without having a document opened. The difference is, Word will open a new empty document when you open it but Unity will open the last project you’ve worked on.

You can however always open a new project. But ‘closing’ a project is the same as closing the editor.

Looks like there is no such option in Unity…There is Open, New, Save, but no Close option… Very strange