I am looking for any good info on gaps on charts, mostly what...

I am looking for any good info on gaps on charts, mostly what constitutes a gap in a chart?


For instance when a stock turns from a lower and gaps up, but it traded in that gap only a few days ago when the stock was moving down, Is that still a gap?

And what parameters must be met before a gap can be ignored, like if there is a gap on the chart from 6 months ago, and the price has moved well up?