In today's society being gender free or politically correct, the person who serves food in a restaurant is sometimes called a 'server'. The is the classification under 'wait staff'. Some restaurants still refer to servers as waitresses or waiters.
someone who works for a business
An employee
computer shop attendant/keeper
a horticulturalist
demonologist
Mason
A gardener.
collector
coach
An electrician.
paver
A co-worker. or colleague