Polystyrene is a hard, solid, and transparent polymer and it is a type of polyolefin used to make a wide variety of consumer products. There are different types of PS which are general-purpose polystyrene (GPPS) and expandable polystyrene (EPS). Polystyrene which has foam properties is called expanded polystyrene (EPS). EPS is a rigid, tough, white, and closed-cell foam that is made of pre-expanded PS beads. EPS is used for disposable trays, plates, bowls, cups, packaging applications, construction, and insulation applications. EPS beads are produced by two basic processes: the batch process and the impregnation method. In this paper, we are going to reveal the different production processes of PS and its global consumption and market.