In this paper, we describe the different database architecture and security measures. The architecture of a database system is greatly influenced by the underlying computer system on which the database system runs. Database systems can be centralized, where one server machine executes operations on the database. Database systems can also be designed to exploit parallel computer architectures. Distributed databases span multiple geographically separated machines. Ensuring the security of databases is also a complex issue when discussing database architecture. The purpose of this paper is to highlight and identify the architectures of database systems running on server systems, which are used in centralized and client–server architectures and the security measures pertaining to database systems.