THIS IS A EASY STUPID QUESTION!!!!!!!

Shock is short form form shock absorber, general term.

strut is short form for damper strut or Mc Pherson strut.

And that's where Mr. Mc Pherson comes into play: While the construction on many VWs is of the coil over shock type (damper/shock absorber sits inside the coil spring) on both front and rear wheels, it's only a Mc Pherson strut if the shock absober is part of the supension. Part of the suspension means here, that the wheel will lack some kind of support if it lacks the shock absober. This is the case on the front - having only a lower transverse control arm would leave the wheel floating around - but not on the rear, where the wheel would still be fixed if it lacks the shock absorber - although the car would sit rather low. ;-)

Ingo