Modern Apple computers have hardware based full disk encryption which means that the drive cannot be removed from one computer and accessed by another. This cannot be disabled.
It is recommended to use the FileVault system present in MacOS to enhance this hardware based encryption by preventing access to the drive even on the computer it belongs to without first providing the login username and password.
If you are using a University Supported Desktop Mac this is done for you, and a recovery key is saved such that support staff can help you should it be required.
If you are using a standalone Mac then you will need to configure FileVault yourself. Apple have information on this at Protect data on your Mac with FileVault
You will be given a recovery key. You should keep this safely and securely as you may need it to regain access to the contents of storage.
Please contact the IS Helpline or your local computing support if you require assistance.