Receipt printers can have either an autocutter or tearbar mechanism built-in to the printer to help separate a printed receipt from the paper roll. 

1. An autocutter printer will have a mechanism embedded inside the printer which is shaped similarly to either a pizza cutter or knife to automatically cut the receipt for an employee. 
   
   
2. A tearbar printer is often used in restaurants or retail environments when an employee manually wants to tear off a receipt for the customer.  Tearbar printers will have a set of jagged teeth positioned above the paper path to help cut the paper when pulled by the employee.