An integer designating the minimum level of the Android API that's required
for the application to run.
Despite its name, this attribute specifies the API Level, not the
version number of the SDK (software development kit). The API Level is always
a single integer; the SDK version may be split into major and minor components
(such as 1.5). You cannot derive the API Level from the SDK version number
(for example, it is not the same as the major version or the sum of the major
and minor versions). To learn what the API Level is, check the notes that
came with the SDK you're using.
Prior to installing an application, the Android system checks the value of this
attribute and allows the installation only if the
API Level is less than or equal to the API Level used by the system itself.
If you do not declare this attribute, then a value of "1" is assumed, which
indicates that your application is compatible with all versions of Android. If your
application is not universally compatible (for instance if it uses APIs
introduced in Android 1.5) and you have not declared the proper
then when installed on a system with a lower API Level, the application
will crash during runtime. For this reason, be certain to declare the appropriate API Level