Veneers are esthetic partial crowns that cover mostly the front side of front teeth where there are stains from fillings or discoloration. It is a conservative approach of the crown so less tooth structure is prepped compared to getting a crown. Not everyone is suitable for veneers.
The front side of the tooth and some portion of the top surface of the tooth is prepped about 0.5 depth. Then an impression is taken for the fabrication of the veneer by the dental lab. You will be wearing a temporary veneer but they are so weakly bonded to the tooth, the temp may easily fall out so you would need to be very careful until your permanent veneer is ready. Once the veneer is ready, it is tried in the chair setting and if everything is fitting good, it is cemented on the tooth.
Can everyone get the veneer?
The answer would be no. Not everyone is suitable for veneer. If you are one of type who genetically prone to a cavity, it may be better to just get a crown. Or if the tooth has filling toward the lingual (back) side of the tooth, it may be better to get a crown instead of getting a veneer to protect the tooth. There are esthetic crowns such as Procera crowns, Emax crowns, zirconia crowns available out there.