Support and resistance lines conform the most basic analytical tools and are commonly used as visual markers to trace the levels where the price found a temporary barrier. In other words ...

Widely used to find intraday support and resistance. They can be combined with session times (e.g., waiting for London session to test R1 or S1 before trading). Session-specific highs/lows ...

Traders use them to determine if a market is trending and, if it is trending, as dynamic support and resistance levels. Many traders also use moving averages as the basis of a trend-following ...