Definition:

A prosthesis used as a replacement for one or more of the teeth or other oral structure. Because patients have different problems with their teeths, there are a lot of different types of prosthesis :

Inlay

It is a prosthetic reconstitution layed in the tooth. It is sealed with a cement. It was previously made of gold.
We have newer materials as composite resins, ceramo-metallic, whole ceramic, and also a better aesthetic result. The main quality is the tooth tissue saved. The defaults are eventual unsealing and resumption of toothdecay.

Inlay-onlay

In that case there is both lay in and lay on the tooth.

Crown

The prosthetic crown avoids dental fracture while the tooth is surrounded by axial inner surfaces of the prosthetic crown in the same way than the metallic surrounded circle in a barrel that keeps together the staves. The part over the tooth is also metallic and is used to avoid alimentation infiltrations synonimous of toothdecay and also to resist at mastication forces.
This is the covering crown.

Bridge

It is a prosthetic whole containing many crowns casted together, aesthetic or not, and replacing one or more absent tooth on the same dental arch. In this way we can make complete bridges concerning the whole dental arch.

Bemovable prosthesis

Those are are unfixed prosthesis that must be take off and washed after every meal. Those prosthesis may be partial or complete, made of resin or with a metallic cast part, with false teeth made of resin or ceramic.

Prosthesis over implants

Implants are manufactured metallic pieces screwed in bored bone cavity with calibrated drills.
This is a surgical intervention and requires a general anaesthesia. Over an implant we have to make casual prosthesis. Those are bridge, crown or intracoronal overdenture attachment used to retain removable prosthesis.