A Communications officer was a specialist crewmember found aboard Federation Star Fleet ships, space stations and Earth postings. The "comm" officer is considered an Engineering position, and is responsible for managing all incoming and outgoing transmissions.
The position was unique in that it could be being manned by officers from three major divisions of starship personal, progressing from science in the 22nd century to command and later to operations in 23rd century.
Starships of the mid to late 24th century did not have a bridge position of communications officer, although the post continued to exist. Communications officers are required to have a specialty in "Operations." Usually, additional training in communications technology, linguistics, and cross cultural communications is required.