If we are talking credit card terminals then this will depend a lot on implementation. You can have whatever you want on a terminal as long as it meets PCI DSS/

If we are talking credit card terminals then this will depend a lot on implementation. You can have whatever you want on a terminal as long as it meets PCI DSS/PED requirements which mostly are concerned with safety and integrity of the transaction. Safety means your PIN and private issuer data (data your bank put on your card) stays safe and integrity means nobody can meddle with the data or the flow of the transaction (so the amount you have approved on the display is the amount of transaction in your bank is the amount printed on your printout, etc.)