What is simulation distance in Minecraft?

Minecraft has a ton of settings that can be confusing for those not elbow-deep in knowledge about the game's engine or how it works, and simulation distance is one of them.

What is simulation distance in Minecraft: Java Edition 1.18?

Simulation Distance: E- chunks - iFunny Brazil

Simulation Distance variable -e flag · Issue #1065 · itzg/docker-minecraft-server · GitHub

Modifying the Render Distance and Simulation Distance Settings on Your Minecraft Server - Xgamingserver

MCPE-78840] Instant despawn radius for simulation distance = 4 is too short - Jira

The Game Changing New Minecraft 1.18 Setting

Most optimised proven bedrock creeper farm! 1.18 4000 gunpowder p/h designed to simulation distance 4 for realms : r/technicalminecraft

Simulation distance – Minecraft Wiki

Simulation distance – Minecraft Wiki

Minecraft 1.18: What is Simulation Distance?