Dentures are removable lab-made prosthetics used to fill spaces where teeth have been lost.
If dentures are replacing a full arch/mouth where all teeth in that arch/mouth have been lost, they're called a "full denture".
If dentures are only replacing a few teeth lost in an arch, they're called a "partial denture".
There are many different options when it comes to dentures which are appropriate in different situations.
Dentures are traditionally acrylic or metal-backed, however modern innovation has led to the formation of "flexi-dentures" and other denture variations which can offer more comfort or better aesthetics.
Providing a denture requires the rest of the mouth to be in good condition, including:
Abscence of disease
Excellent oral hygiene
Smoking cessation advice
The denture making process takes a number of appointments (4-6) with 2 weeks between each appointment due to lab waiting times.
Many patients get on very well with dentures, but unfortunately some do not.
You may wish to consider other options (depending on clinical appopriateness) such as implants and bridges where possible.