All functions can use 3 diffrent variations of position. For most examples, the first one will be used.
pos(0,0,0) - Places a block adjacent to player X,Y and Z position
posLocal(0,0,10) - Places where the player faces. It uses the parameters left/right, up/down and forward/backward. I recommend sticking to just changing the last value
world(0,0,0) - Places a block at a world coordinate (X,Y and Z)
Coordinates can be turned on in the settings.
Spawn a mob (hostile mobs will not spawn in peaceful mode).
This example spawn a chicken 10 blocks above the players head
Kills all mobs and enenties (minecarts, armour stands ect). This does not include the player.