Track or roller binding
A bent track or worn roller catches the door at one point.

Door movement
A door that stops partway up or down can point to an opener setting, a sensor issue or a mechanical problem like a broken spring, bent track or binding roller. Because some causes involve high-tension parts, careful observation is the safest first step.
Short answer
If the door stops at the same spot every time, look for a track problem or binding roller there. If it stops at random points, the opener's force or a sensor may be involved. If it stops after a bang and feels heavy, a spring may have broken. Avoid forcing the door and book a technician when the cause is mechanical.
A bent track or worn roller catches the door at one point.
The opener may stop because the door is too heavy to lift. See spring replacement.
The opener reads normal resistance as an obstruction and stops.
A slipped or frayed cable can make one side drag and stop the door.
Describe what the door is doing when you call. A provider may ask follow-up questions, but a reliable price normally needs an on-site look rather than a phone-only quote.

Garage door repair covers the moving system as a whole: springs, cables, rollers, hinges, tracks, the opener and its safety sensors.

Vertical tracks run up each side of the opening and curve into horizontal tracks under the ceiling.

Most homes have torsion springs on a shaft above the door or extension springs that run along the horizontal tracks.
That usually points to a mechanical catch at that point, such as a bent track, a damaged roller or a hinge that binds as the door curves.
Yes. If the door is too heavy for the opener, the opener may stop partway to protect itself. The door will feel very heavy if lifted.
If the door is level and moves freely, closing it with the opener may be fine. If it is crooked, heavy or a cable is loose, leave it and book service.
Yes. Worn gears, a failing motor or incorrect force settings can cause stops. A technician tests the opener and the door separately.
Heat can dry out rollers and expand parts, adding friction. It can also stress opener electronics. If stops increase in summer, a tune-up may help.
Mention where the door stops, whether it is level, any noises and whether it started suddenly after a bang.

Call to schedule a technician visit with an independent provider who serves your area.