The Covering Tour Problem (CTP) is considered as a generalization of the Traveling Salesman Problem in which not all nodes must be visited. The main concept of the CTP is that some nodes must be visited by the vehicles whereas some other nodes have to be covered. If a node is located within a predetermined covering distance of its next visited node, it is said to be covered. The interest in this subject has recently increased, both theoretically and practically. Multiple researchers have been interested in the CTP for real-life applications, such as humanitarian logistics, regional development, urban patrolling, and healthcare management. To the best of our knowledge, no work has considered reviewing the covering tour problem. For this reason, we will introduce in this work, the CTP and its different variants. The main objective is to examine the existent literature to highlight the studies that have already been done and to identify any gaps and promising areas for further studies.