I have also been confused with this one and I will give my take on it as it relates to my trading systems.
My method is to find higher time frames where there is current or potential momentum and look for a combination of factors such as breakouts and moving averages to confirm momentum with a confluence of events that include trend line bounces and candle patterns and breakouts to confirm entries. This methodology is reliant upon the human brain understanding complexity and is impossible to program into a computer.
Within that methodology there are systems, one system is one version of the 10XROI system which is to wait for strong momentum evidenced by the moving averages, wait for a push-pull set-up pull-back after a strong second candle, wait for a sideways move at that level on the hourly chart creating a s/r zone, wait for a breakout from that with a stop loss that goes below the previous S/R level and which allows a 10XROI Take profit (eg 30 pips).
You could take this system and probably program it into a computer, it also back tests very easily however it is much more difficult to back test a methodology.
Anyway that is my take on it …