Approaches are named based on the navigation system required to execute the approach. A VOR approach requires a VOR receiver. A VOR/DME approach requires both a VOR receiver and DME system.
Most approaches are aligned with a runway and will include a runway number in the approach title (VOR RWY 25); these approaches include straight-in landing minimums to the runway in the title. Some approaches are published that only have circle-to-land minimums; those approaches will have a letter at the end of the title (VOR-A).