Manifest file plays an integral role as it provides the essential information about your app to the Android system, which the system must have before it can run any of the app’s code. Manifest file performs various tasks such as:
Manifest file names the Java package for the application as the package name serves as a unique identifier for the application.
It protects the application by declaring permissions in order to access protected parts of the API and interact with other applications.
Manifest file declares the minimum level of the android API and list the libraries which is linked with the application.
Manifest file list the instrumentation classes which provide profiling and other information as the application runs, but this information is removed as soon the application is publishes. It remains only till the application is in development mode.