The price gap is a jump between two periods of time
They are considered as support and resistance lines
There are three types that I use when I trade
1/ breakaway gap: it occurs in the first of a trend line, it is the most profitable gap that you must trade, we expect that the price will reverse its direction aggressively.
2/ runaway gaps: they occur in the middle of a trend line, they could be supported and resistance lines.
3/exhaustion gaps: they occur at the end of a trend line, they are not tradable and not profitable and you must avoid them.
Hope I help