The resting metabolic rate is the amount of energy (calories) required by the body to function at the resting state. This measurement has into account basic metabolic activities, including energy (calories) used to eat.
The resting metabolic rate includes different metabolic activities:
breathing
circulation of blood
organ functioning (e.g., digesting food)
basic neurological functions
The resting metabolic rate of the metabolism is measured in strict and steady (resting) conditions.
On the other hand, the basal metabolic rate measures the minimum amount of energy (i.e., calories) required to perform the most basic life-sustaining functions.