Health: white bar
Armor: yellow bar  
Shields: blue bar

Health bars are broken into 25-point increments. In addition to regular health shown on this bar, heroes may also have armor and shields

Health armor shields
Symmetra

Shields

Shields will be the first thing depleted when damage is taken (over health & armor).

Once a hero has been out of combat for 3 seconds, the shield will restore at  25 per second.

A shield is the only hit-point value to regenerate itself over time and  can also be healed the same ways as normal health.

Shields from base hero stats and shields granted by Symmetra all behave the same.

Armor

Armor will be depleted before health but after shields.

Armor will block 5 damage from every individual projectile hit that deals 10 damage or more.

If an individual projectile does less than 10 damage, it will be halved. This means that armor is very effective against rapid fire weapons, beams, and shotguns. It also means those heroes will be charging their ultimate at half the normal rate.

Bastion, D.Va, Reinhardt, Winston, and Torbjorn with Molten Core all have base armor that can be healed. However, armor from Torbjorn’s armor packs cannot be healed, it can only be refilled by another armor pack.

Contrary to popular belief, armor is no longer healed at a 50% increased rate.

Winston
lucio

Over...shield?

icon-ability (23)While there is not technically an overheal ability in Overwatch, Lucio’s Sound Barrier acts very similarly to one.

Lucio’s ultimate grants heroes with a large, rapidly decaying “shield” of 500 hitpoints. The shield degrades at a rate of 100 hitpoints per second over a span of 5 seconds until it’s depleted.

This ability will be prioritized before any other hit-point value.

Since this “shield” does not regenerate and is actually represented by an even darker blue bar, it’s much closer to the mechanics of an overheal than a shield. However, it’s important to note that Lucio’s Sound Barrier does not heal missing health.