Heat shoes are an electrically-heated cylinder-shaped “shoe” with a heating element inside, which the film is pulled across and the rollers apply pressure.
Heated rollers utilize a heating element which is embedded in the center of two nip rollers; the film is heated as it comes around the nip roller.
The rollers apply both heat and pressure to the film. Heated-rollers typically offer a slightly better bond than heat shoes. Heat rollers will often increase the bond strength on digital prints.