What a shield actually blocks
Hold right-click with a shield (6 planks + 1 iron ingot) and melee hits, arrows, tridents and most projectiles hit the shield instead of you — including creeper blasts at point blank, which makes it the ultimate creeper counter. Knockback is also negated while blocking, so you can walk through a skeleton volley untouched.
The axe problem
An attacking player (or piglin brute... rather, mob-free context) wielding an axe can disable your shield for 5 seconds on hit — the classic PvP counter. Against melee PvE the shield has no such weakness. If an axe-wielding rival disables your shield, back off for the 5 seconds or swap to ranged.
Offhand and enchanting
The shield lives in your offhand — your main hand stays free for the sword or torches. It accepts Unbreaking III and Mending, and can be dyed with banners for a custom crest. Rare but real: a hit with more than ~8 damage can chip through, so keep Mending on it.
