Glass microspheres are microscopic spheres of glass manufactured for a wide variety of uses in thermal insulation coating, putty, plastic casting polyester, radome, synthetic foam, adhesives, printed circuit board substrate, bowling, fan blades, and caulking materials, emulsion explosives, golf, sealant, pipeline insulation materials, artificial marble, PVC, low density oil drilling, light cement etc. Glass microspheres are usually between 1 and 1000 micrometres in diameter, although the sizes can range from 100 nanometres to 5 millimetres in diameter. Microspheres are spherical particles that can be distinguished into two categories; solid or hollow. This paper presented a general overview of glass microspheres.