How does message arbitration work on a CAN bus?

CAN uses non-destructive bitwise arbitration to resolve bus access conflicts. When multiple nodes transmit simultaneously, they compare their transmitted bits to the bus state. A dominant bit (0) overwrites a recessive bit (1). Nodes transmitting recessive bits while sensing dominant automatically stop transmitting and become receivers. The message with the lowest identifier (highest priority) wins arbitration and continues transmitting. This ensures deterministic behavior where higher-priority messages always get through without collision or retry.