Meaning – In the context of computing, the term extended architecture, is a standard is a specification released in 1991 by X/Open for distributed transaction processing(DTP).
the main objective of extended architecture is to guarantee atomicity in “global transactions” that are executed across heterogeneous components. A transaction is a unit of work such as transferring money from one person to another. Distributed transactions update multiple data stores.
Since XA uses a two-phase commit, the advantages and disadvantages of that protocol generally apply to XA. The main advantage is that XA (using 2PC) allows an atomic transaction across multiple heterogeneous technologies, whereas traditional database transactions are limited to a single database.