Basic purpose of this lecture is to presentation on Parallel Databases. Parallel databases system seeks to further improve performance through parallelization of numerous operations, such because loading data, making indexes and checking queries. Although data could possibly be stored in any distributed fashion, the actual distribution is dictated solely by effectiveness considerations. Parallel databases enhance processing and input/output speeds by using multiple CPUs as well as disks in parallel. This lecture also briefly explain: I/O Parallelism, Interquery Parallelism, Intraoperation Parallelism, Design of Parallel Systems, Intraquery Parallelism, Interoperation Parallelism etc. with example and explanation.