This document summarizes the different types of mechanical seals. It begins by introducing mechanical seals, packings, and gaskets which are used to prevent fluid leakage and foreign material penetration. Seals are selected based on factors like pressure, temperature, medium, environment, and shaft speed. Seals are classified as either static or dynamic. Static seals include gaskets, direct contact seals, and sealants. Dynamic seals include those used on rotating shafts like interfacial and interstitial seals, and those used on reciprocating shafts like packings, diaphragms, and rings. The document describes examples of different seal types and concludes with factors that influence the leakage rate of mechanical shaft seals.