See how the WW2 has just plain olive green no camouflage really to it just plain. the helmet is more like a bowl, no Bulletproof vest and uncomfortable boots called gator boots.
Modern day soldier has more of a digital camo green and tan look, there is a Bulletproof vest that holds multiple mags for the M4A1, the Helmet is more head fitting, and bulletproof, the boots are more comfortable, more breathable and weatherproof.