A root canal is a treatment used to overhaul and protect a tooth that is badly decomposed or infected. It is the hollow part of a tooth that includes the nerve tissue, blood vessels, and other cells, also known as the pulp. Pulp sits within a space called the pulp chamber and this goes down into the roots of the tooth. The pulp chamber within the root is called the root canal. So, it actually means inside the tooth. During a root canal process, the nerve and pulp of the tooth are removed and the inside is cleaned and preserved.