Support and resistance levels are points where a chart experiences recurring upward or downward pressure.
A support level is usually the low point in any chart pattern (hourly, weekly or annually), whereas a resistance level is the high or the peak point of the pattern.
These points are identified as support and resistance when they show a tendency to reappear. It is best to buy/sell near support/resistance levels that are unlikely to be broken.
Once these levels are broken, they tend to become the opposite obstacle. Thus, in a rising market, a resistance level that is broken, could serve as a support for the upward trend, whereas in a falling market; once a support level is broken, it could turn into a resistance