The root canal treatment procedure is endodontic in nature. It means that the treatment involves the inside of the tooth, particularly, the dental pulp.
It actually deals with the multiple layers which consist of the inner structure of the teeth or the ones beneath the teeth enamel or the visible outer layer of the teeth. The inner layers include the dentin (the hard layer) which encloses the interconnected root canals and the pulp chamber. Inside them is the dental pulp which is described as a combination of nerves, blood vessels and connective tissues.
During a root canal treatment, the dental pulp is removed entirely or repaired, depending on the condition of your teeth.
Usually, after the root canal treatment is done, the affected teeth are also restored to its normal state, including its functionality. However, this would require another treatment involving other dental procedures.