High pressure occur at node and low pressure at antinode.
Imagine standing in a queque. You are the node i.e you dont move . To the left and right of a node is displacement in opposite sign (direction) So in the queque the person if front of you will push towards you and so did the person behind you also did the same . Dont you feel squashed up! Particles in that squashed up location is the node having high pressure.
