What does getActivity() mean?

What does getActivity() mean? I saw in somewhere, they wrote MainActivity.this.startActionMode(mActionModeCallback) instead of getActivity(). could someone explain what this two lines mean?

  someView.setOnLongClickListener(new View.OnLongClickListener() {
        // Called when the user long-clicks on someView
        public boolean onLongClick(View view) {
            if (mActionMode != null) {
                return false;
            }

            // Start the CAB using the ActionMode.Callback defined above
            mActionMode = getActivity().startActionMode(mActionModeCallback);
            view.setSelected(true);
            return true;
        }
    });

Solution 1:

Two likely definitions:

• getActivity() in a Fragment returns the Activity the Fragment is currently associated with. (see http://developer.android.com/reference/android/app/Fragment.html#getActivity()).
• getActivity() is user-defined.

Solution 2:

getActivity() is used for fragment. For activity, wherever you can use this, you can replace the this in fragment in similar cases with getActivity().

Solution 3:

getActivity()- Return the Activity this fragment is currently associated with.