The chapter starts with what is composite? Then deals with problems with earlier tooth coloured restorative materials, explains in length about the evolution of composites. Then the chapter deals in length about the various components in a composite resin its properties and characteristics. Detailed explanation about various classifications applied for composite is explained and various types of composites explained. Next section explains about curing of composites both self curing and light curing is explained, problems in light curing like polymerization shrinkage and methods to deal with it is outlined. Other properties like marginal leakage and wear of composites is explained. The chapter concludes with discussion about indirect composites, finishing of composite restorations, repair and rebonding of composites.