The platform (bed) on the 3D Printer that your part prints on is called a build plate. Some build plates are heated and some are not depending on the printer or filament being used. Most build plates are made of glass, but there are some other material used as well. Many filaments will not stick easily to the build plate surface alone, so an additional coating of a disposable material if often used to assist in build plate adhesion. There are a wide variety of materials available including adhesive films, tape, glue sticks, and brush on liquid solutions. The coatings available also often make it easier to remove your finished part from the build plate.