Mob is short for mobile. A mob can move around and has health. The health of a mob differs on what kind of mob it is. It could have as much as 200 health points or as little as 1 health point. It could also be as big as 3.5 blocks tall or as small as 0.5 blocks tall. It is also either hostile, neutral, or passive. Hostile mobs attack you when they catch sight of you, neutral mobs attack you if provoked, and passive mobs don’t attack you, act like you’re not there, and run away if attacked. If any mob’s health goes to 0 or lower, congratulations, you’ve killed it.