When I read some events map, I found loops used wildly. But some equipment watches like Timex used laps. What's the difference, how can I use them correctly? Please also give some sample if possible.
It appears to be the case that a loop is the word you would use to describe all or a section of a course or track which repeats upon itself (i.e. in a loop). In contrast, a lap is the description of physically running around that loop more than once.
From the online Cambridge dictionary for lap:
a complete journey around a race track that is repeated several times during a competition
The definition of loop has no reference to "looping" around a race track, but it does state, as an example:
Turn left where the road loops round the farm buildings.
This implies that loop could be used to describe the curved path something takes, which at a stretch suggests it could be used in place of lap, but it certainly doesn't seem like intended usage.