SOAP (Simple Object Access Protocol) is its own protocol, and is a bit more complex due to more defining standards than REST—things like security and how messages are sent. These built-in standards do carry a bit more overhead, but can be a deciding factor for organizations that require more comprehensive features in the way of security, transactions, and ACID (Atomicity, Consistency, Isolation, Durability) compliance. For the sake of this comparison, we should point out that many of the reasons SOAP is a good choice rarely apply to web services scenarios, which make it more ideal for enterprise-type situations. Higher levels of security (e.g., a mobile application interfacing with a bank). SOAP has tighter security. WS-Security, in addition to SSL support, is a built-in standard that gives SOAP some more enterprise-level security features, Messaging apps that need reliable communication. Rest doesn’t have a standard messaging system and can only address communication failures by retrying. compliance. SOAP has built-in ACID compliance. ACID compliance reduces anomalies and protects the integrity of a database by prescribing exactly how transactions can interact with the database.