+P and +P+ are higher pressure and higher velocity.
Glocks will shoot these forever. I run nothing but +P+ factory and reloads in my Glock and my SIGs.
My G-17 has digested over 12000 +p and +P+ and shows no signs of wear.
The nation that will insist on drawing a broad line of demarcation between the fighting man and the thinking man is liable to find its fighting done by fools and its thinking done by cowards.