Across Vault, two types of API are used:

RESTful APIs: For synchronous interactions and Kafka-based streaming APIs. These are the primary interfaces which are used by clients to integrate with the Platform Layer. The RESTful APIs are synchronous APIs designed to be used where the current state of a resource or set of resources needs to be retrieved, or resources of the system must be mutated. This can support a wide set of use cases including supporting customer channel applications and back-end systems.

Streaming APIs: Asynchronous APIs designed for use cases where near real-time receipt of events occurring in the Platform Layer is required to enable notifications and for real-time analytics; and, where downstream databases should be populated as events occur for data warehousing, and querying and large-scale and/or offline analysis.

For more complex processes with branching and transform logic, Vault Workflows can be used to orchestrate these processes, interacting with both Vault APIs and systems outside of Vault.

An application programming interface is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how to build or use such a connection or interface is called an API specification.

Ans: API is the abbreviation for Application Programming Interface. It specifies how two modules of software communicate with one another. There are various types of APIs, but the swagger is focused on the Web API.