Answer:
By Email, push notifications, or version Upgrades.
Step-by-step explanation:
In other words, ongoing maintenance lets programmers update their software so users can continue to enjoy it for a long time to come.
These updates might come through email, push notifications (you know the little popup notices you get on your phone?), or version upgrades. For the user, it's usually just as simple as pressing an "update" button when the programmer sends a change. Some updates even happen in the background as the computer or device is running. For those, you may never even know the update happened!