Systematic trading strategies follow rules. Trend following rules are common and may focus on short-, medium-, or long-term trends. Contrarian strategies exist but are less common.
Discretionary trading strategies depend on the judgment of the manager and could be based on economic or other criteria. Q: Does systematic trading also called computer program based trading (Or something similiar)?
If you are just after description - then it can also be called “Mechanical” or “rules-based” trading.