Graphene is a two-dimensional gapless semiconductor with high carrier mobility, in which the low-energy excitations are massless, chiral, Dirac fermions. It is currently the world's thinnest and hardest nanomaterial. It has good optical, thermal, and mechanical properties. This paper aims to review the development of graphene as well as the research focus in recent years. Specifically, a variety of growth methods and process parameters to improve the performance of graphene are introduced. The merits and demerits of each growth method are also discussed. In addition, graphene thin films may be used as an electrode in solar cells and light-emitting diodes, owing to high transparency.