Manhole

The main difference between manholes and handholes is simply the size of the hole. The term "manhole" refers to inspection holes installed on the pipeline or manhole of a communication system, which can accommodate a person to pass through (either by crawling in or out) during inspections or maintenance of such equipment. In contrast, a handhole is smaller and only allows for hands to be inserted for inspection or operation. Additionally, both manholes and handholes are not only required in communication engineering but also in complex systems such as HVAC (mainly central air conditioning) and power line systems, where such inspection openings are typically provided.