Trend following is exactly what it sounds like. Pick a trend(over a time frame you choose, using a set of indicators you choose), then join the market on the side of the trend. To be successful, you must join the trend early, and be vigilant and disciplined enough to cut your losses when your trend fails to gain momentum and/or reverses.

From https://investresolve.com/blog/over-two-centuries-of-global-... (linked to in the bloomberg article) :

Trend and momentum are defined as the 12-month-minus-1-month excess return. While this is consistent with traditional measures of cross-sectional momentum, “trend” as proposed by Moskowitz, Ooi and Pedersen; and Hurst, Ooi and Pedersen does not impose a skip month. The current authors make the case that a skip month is more conservative because it allows for a delay in data diffusion in very early periods.

It's pretty similar to momentum investing, except using real returns rather than relative performance: https://www.aqr.com/Insights/Research/Journal-Article/Fact-F...