The world is always changing. Airports change frequencies or close, new radio towers are built, approaches are changed.
For this reason, a GPS database has an expiration date. After that date is passed the GPS can’t be used for IFR anymore.
Of course, nobody would buy a GPS that suddenly just can’t be used so the database can be updated.
Unlike your phone, the GPS in your plane needs to be reliable, so it can’t count on getting data over a data connection. Instead, modern GPSs use data cards to stay up to date.
In the image above one of the data cards has been pulled out of the slot. You can see the empty slot under the OBS button.
To update you just buy the latest database card and swap it out. That’s it.