1. I had breakfast 2 hours ago.
2. I am having breakfast.
3. I have had breakfast recently.
4. I have been having breakfast for 10 minutes.
NUMBER 1: my breakfast finished at a specific time in the past. (Simple past)
NUMBER 2: describes an activity that is in progress right now (present progressive)
NUMBER 3: tells us the action happened but occurred at an unspecified time in the past.. (Present perfect)
NUMBER 4: in this example the action began in the past and is progress now. (Present perfect progressive)