another example, with a user-management system, an application can
call an API to validate and authenticate users.Figure 7-2 Service API Providing a Complete Service
to the Calling Application
Information API: An information API allows one application to ask
another application for information. Information in this context can
refer to data gathered over time, telemetry data, or a list of devices that
are currently connected. Figure 7-3 provides a visual representation of
an information API.Figure 7-3 Information API Providing Information
or Analysis of Data That Has Been Collected
Hardware API: Application developers use hardware APIs to gain
access to the features of hardware devices. Usually these APIs
encompass some kind of hardware or sensors, and an application can
call this kind of API to get the GPS location or real-time sensor data
such as temperature or humidity. Figure 7-4 provides a visual
representation of what a hardware API does.