A denture is designed to fill in the gaps left by one or more missing teeth. It is either a plastic or metal plate with a number of false teeth attached to it.
If partial, it can clip onto some of your natural teeth via metal clasps, which hold it securely in place in your mouth. It can easily be unclipped and removed.
Your dentist will be able to take measurements of your mouth and order this for you, or you can see a qualified clinical dental technician, who can provide a full / partial denture for you directly after you have first seen your dentist for a treatment plan and certificate of oral health.