Notifications alert you to many things on your iPhone and iPad, including incoming messages, new emails, and calendar events. You can even set up location-based alerts.
Some apps use your location to send you relevant alerts based on where you are. For example, you might get a reminder to call someone when you get to a specific place or when you leave for your next location.
If you don’t want these type of alerts, you can turn them off. Go to Settings > Privacy > Location Services, then tap an app to turn alerts on or off based on your location.
(This how-to is based on my experiences and info on Apple’s support pages — where the images sometimes come from.)