Does data save once you leave an activity android

Quick question: I have an application that populates a listview with user input data from another activity;however, whenever I enter that data into the second activity then return to the listview activity I see it populated with the values I entered. But, if I return to the second activity again, enter the values, and go back to the listview activity, I see the new values updated but the old ones have disappeared. Now, I don't know if I'm not updating the listview correctly or if I need to use sqlite databases to store this data or shared preferences in order to update the listview to new data while containing the previous information.

Thanks for any help.