Yes, I expect this thread to be moved and/or locked.
But to answer your question...
Celerons are produced for both Slot 1 and Socket 370. FC-PGA processors go into Socket 370, while the slot 1 processors go into slot 1. socket 370 looks like what you might stick an original flat pentium into, except it has more pin grid holes (370 to be exact). Slot 1 processors go in like RAM and look like a COAST with a box around it.
Socket 370 processors are earier to install. If you have a slot 1 motherboard, then you can buy a Slot-to-Socket(Slocket?) adapter for $20 and you can run an FC-PGA chip on a slot 1 mobo.
Hope this is what you're looking for!