Understanding APIs: REST
Security orchestration, automation and response (SOAR) platforms rely heavily on APIs (application programming interfaces) to drive orchestration of disparate security tools (products) and invoke desired responses in the form of actions. Besides SOAR products, APIs are commonplace among almost all services, tools, and products used by technical workers.
Even though APIs are extremely common, you may not have experience using them or even know that a service has one when interacting with it. For example, Facebook uses an API framework called Graph API.