Adjustment is no longer available
From 2022 you can use Clearing to change universities if your results are better than expected.
As of 2022 UCAS Adjustment no longer exists.
Adjustment used to be the process whereby you could 'trade-up' to another university if you got better exam results than you expected. This process is now handled through Clearing.
So if your exam results are better than you expected and you want to apply to a different university you can release yourself into Clearing and apply to your new chosen university through Clearing.