Depends on the switchgear and protection system design. Is it bus differential protection, zone interlocking, straight overcurrent, directional overcurrent or some other protection scheme?
The terms are often interchangable in my experience. Some people refer to busbar protection as bus zone. Usually the busbar protection protects defined zones, eg Busbar Section 1, section 2, main busbar, reserve bar etc.
If want to learn how to test busbar protection don't try to do it on an internet forum. It's probably the riskiest protection of all to test, and many a protection engineer has tales to tell about how they blacked out a substation whilst testing busbar protection. You really need to know what you are doing.