This review presents various types of epoxy resins and curing agents commonly used as composite matrices. A brief review of cross-linking formation and the process of degradation or decomposition of epoxy resins by pyrolysis and solvolysis is also discussed. Mechanical engineers are given a brief overview of the types of epoxy resin, which are often applied as composite matrices considering that they currently play a large role in the research, design, manufacturing, and recycling of these materials.