One of the most useful things about Android development is the intents dispatching mechanism. As Google says, An intent is an abstract description of an operation to be performed, and just to be clearer, continues saying, An Intent provides a facility for performing late runtime binding between the code in different applications. Its most significant use is in the launching of activities, where it can be thought of as the glue between activities. It is basically a passive data structure holding an abstract description of an action to be performed (http://developer.android.com/reference/android/content/Intent.html).
Intents are widely used in Android, and if you want to fully integrate your Delphi app with the Android OS, you will probably have to deal with Intents. Delphi uses intents internally to deal with some fundamental Android services (TShareSheetAction...