"Arny Krueger" wrote in message

Service - the act of serving or assisting someone. This includes both
repairing and maintaining. It also includes many other things such as
serving food.

Repair - the service of correcting a fault, such as those due to wear and
tear, or accident.

Maintenance - routine service that puts off or circumvents common faults
by making premptive changes to areas subject to predictable degradation,
such as cleaning and applying fresh lubrication to a bearing.

IOW, both repair and maintenance are services, but many other things are
services as well. In general the same service organizations and service
people provide both repair and maintenance. The office copier service man
repairs faults and also performs scheduled maintenance.

You've nearly got it!

Just swap the two words Service & Maintenance over above and you're spot on.

Maintenance includes both service and repair.
By servicing and repairing as necessary you maintain the continued optimum
function of something.