How to switch between two activities? : I have two activities 1. rfidReaderActivity 2.TravelActivity
When I read the card i go to the TravelActivity and calculate startingLocation(latitude,longitude) and go back to previous activity(rfidReaderActivity)

Then again when i read the card I need to go to the TravelActivity and this time i will calculate destination and distance traveled. 

So how it can be done to switch between them, considering that the TravelActivity is not destroyed.

Please explain, i have poor understanding about activityLifecycle.

