What does the word "workmen" mean here?

Workmen can be people like plumbers, people repairing appliances, people installing stuff like carpets and such, electricians...all the people who come to do various things that need doing in homes from time to time.

A cleaner certainly COULD be described as a workman, but they generally get called cleaners.

The cat could greet them at the door because they generally knock at the door to be admitted, and the cat obviously goes to the door to greet people.