The short version
Buy the booster box when you want the lowest cost per pack and a full rarity spread. Buy a bundle when you want a sealed, giftable amount of packs without the box price.
Browse sealed TCG.
Guide
Booster bundle vs booster box
A booster box is 36 packs from one expansion. A booster bundle is a smaller sealed pack of packs (often six). The box is the lower cost per pack; the bundle is the smaller outlay.