Database Architecture refers to the structured design and organization of a database system. It defines how data is stored, accessed, and managed, ensuring efficient data retrieval and manipulation. Common architectures include relational databases, which use tables to organize data, and NoSQL databases, which offer more flexible data models. The architecture typically consists of three layers: the internal layer, which deals with physical storage; the conceptual layer, which represents the logical structure of the data; and the external layer, which provides user views. This layered approach helps in managing complexity and improving data security and integrity.