This is the basic RSI, with more levels. The 80, 50 & 20 levels has been added. When the RSI is above the 50 level, it can be considered to be a uptrend. When the RSI is below the 50 level, it can be considered to be in a downtrend. However this is just an indication, price action is the best way to determine whether price is in an uptrend or downtrend.