ESP (extra-sensory perception) is a rendering layer drawn over the game: boxes or skeletons on players, health and armour bars, names, distances, held weapon, and snaplines showing where someone is looking.
The half people underrate is world ESP — loot, containers, extracts, quest items, vehicles and spawns. In extraction and survival games that information is worth more than aim, because it decides where you go, not just what happens when you get there.
A good implementation also gives you a 2D radar, per-category colours, distance limits so the screen stays readable, and streamproof rendering so the overlay never reaches OBS or a Discord capture.
Buyers search for this module under a few different names — Escape From Tarkov ESP cheat, Escape From Tarkov player ESP, Escape From Tarkov loot ESP, Escape From Tarkov item ESP, Escape From Tarkov visuals hack — and they all describe the same thing: the esp module in the Escape From Tarkov editions listed below.