Natural Cover
Using the terrain's built-in walls, pillars, and obstacles as a base to hold position while minimizing exposure.
Holding a frontline is decided by access to cover, not by HP bars. Whether you have taken "one cover further up" is what a Forward Hold actually is, and Dribble's in-and-out runs off natural cover the same way. The moment you step into open terrain with no cover is the most dangerous one, and everything from Sigma/Rein deciding "which pillar do I base off" to a DPS taking corners is an extension of the same idea. Unlike ability cover such as Mei Wall or Winston Bubble, natural cover costs no CD and is therefore always available — that is its greatest strength. Map knowledge and the read on "how deep a corner can I pull back to before the next shot arrives" translate directly into skill gaps.
A tank holding position while maintaining the frontline. A DPS using a corner to keep landing damage one-sidedly. A support securing the heal line while breaking sightlines.
Drifting too far off cover until you can no longer break LOS. Depending on cover so heavily that you stop functioning at all on terrain with little of it.
Forward Hold
Holding a defensive formation pushed into enemy territory to disrupt their regroup.
Dribble
Tank repeatedly steps in and out to bait cooldowns and ammo without ever committing.
High Ground
Elevated map position offering downward sightlines, cover, and safe retreat — the foundation of most setups.
Space
Physical control over the favorable parts of the map — high ground, routes, sightlines.
LOS Break
Stepping into cover to break enemy sightlines, forcing a reset of incoming damage and lock-on abilities.