A Context is a handle to the system; it provides services like resolving resources, obtaining access to databases and preferences, and so on. An Android app has activities. Context is like a handle to the environment your application is currently running in. The activity object inherits the Context object.
Typically you call it to get information regarding another part of your program (activity, package/application)
You can get the context by invoking getApplicationContext(), getContext(), getBaseContext() or this (when in the activity class