Which statement best describes an API?

Which statement best describes an API?

• A. A specification that defines how software components interact by exposing libraries and call conventions
• B. A file system protocol for storing data
• C. A cloud service for hosting databases
• D. A user interface framework

Answer: (A)

An API is a set of rules that defines how software components talk to each other. It specifies what functions or methods are available, what inputs they expect, what outputs they return, and the conventions for making calls. This makes it possible to use existing libraries or services without needing to know how they work inside, just how to interact with them. The description given matches this idea by mentioning libraries and call conventions, which are central to how APIs enable communication between software pieces. The other options describe things that aren’t about defining how software components interact. A file system protocol relates to how data is stored and retrieved, not how programs talk to each other. A cloud service for hosting databases is about providing a managed service, not the interface for using it. A user interface framework is about building UI elements, not the mechanism for software components to interact via defined calls.

An API is a set of rules that defines how software components talk to each other. It specifies what functions or methods are available, what inputs they expect, what outputs they return, and the conventions for making calls. This makes it possible to use existing libraries or services without needing to know how they work inside, just how to interact with them. The description given matches this idea by mentioning libraries and call conventions, which are central to how APIs enable communication between software pieces.

The other options describe things that aren’t about defining how software components interact. A file system protocol relates to how data is stored and retrieved, not how programs talk to each other. A cloud service for hosting databases is about providing a managed service, not the interface for using it. A user interface framework is about building UI elements, not the mechanism for software components to interact via defined calls.