API Level

What is API Level?

API Level is an integer value that uniquely identifies the framework API revision offered by a version of the Android platform.
The Android platform provides a framework API that applications can use to interact with the underlying Android system.

The framework API consists of:

A core set of packages and classes
A set of XML elements and attributes for declaring a manifest file
A set of XML elements and attributes for declaring and accessing resources
A set of Intents

A set of permissions that applications can request, as well as permission enforcements included in the system
Each successive version of the Android platform can include updates to the Android application framework API that it delivers.Updates to the framework API are designed so that the new API remains compatible with earlier versions of the API. That is, most changes in the API are additive and introduce new or replacement functionality. As parts of the API are upgraded, the older replaced parts are deprecated but are not removed, so that existing applications can still use them. In a very small number of cases, parts of the API may be modified or removed, although typically such changes are only needed to ensure API robustness and application or system security. All other API parts from earlier revisions are carried forward
without modification.

The framework API that an Android platform delivers is specified using an integer identifier called "API Level". Each Android

platform version supports exactly one API Level, although support is implicit for all earlier API Levels (down to API Level 1).

The initial release of the Android platform provided API Level 1 and subsequent releases have incremented the API Level.

The following table specifies the API Level supported by each version of the Android platform.