Instantiating a prefab that is in my project folder?

Dunno if this is a dumb question and am I missing something obvious…

So far in my limited work with UNI I declare a public GameObject in a c# script and drop into it a prefab (that I have created in the Project tab). I can now instantiate that prefab in my running game.

But can I instantiate a prefab that only exists in my project tab?
What would be the c# code to find the prefab? Could I use the ‘tag’ to find a game object that is in the Projects tab?

Put the prefabs in Resources Folder if you want Multiplayer somewhere along the road.

put tat prefab into Resources folder(create one , under assets folder) then use Resources.Load to load it into prefab variable,then you could instantiate it …