Anti Personell HE. You use it against bunched up people and structures.

InstaGoat please read before post. I know what HE is. I was talking about the AP missile. AP stands for armor piercing and it's not used to blow people up.
If it stands for anti personnel, why do we need it when we already have the HE round while it's better at this job?

The AP is armor piercing in this case, it says so in the description of the round ingame. However it is probably a mis-labelling, as it very effective versus infantry. So you are both sort of right :)

I though AP stands for "Anti-Personel" or was I wrong?

The round ingame is mislabeled. The correct round against vehicles is the AT round (this will lock.). If the AP round is armor piercing, then idk what use it is, since we already have an AT missile.

I think it should be named Anti-personnel.

I think it should be a Anti Personnel missile.

HE and AP difference is that HE is just high explosive what is used against soft targets and lightly armored vehicles where its high explosive payload cause shockwave to destroy/kill.
AP is only used against infantry where in explosion it release fragments what kill or injure infantry at further distance than HE shockwave does.

Anti Personnel would be more effective killing/injuring infantry at larger area than HE is. But HE is more effective when there are structures like walls as it blows them and cause spalling behind the wall.

It does not make sense that a missile launcher like Titan Compact would have a Armor Piercing because AP effect is using pure kinetic energy to punch trough armor and missiles does not have that kind velocities to come even close.

Missiles what are against armored vehicles should be HEAT meaning when they explode the melted copper stream is directed to armor and it push trough the armor because high pressure.

HEAT capability to penetrate armor doesn't change with distance but stay same.
Kinetic (AP) capability to penetrate armor is directly tied to distance so longer distance = less penetration
HE capability is same as with HEAT, it stay same.
And same thing is with Anti-Personnel rockets and missiles that their effect stay same.

The Titan Compact launcher does not have HE missiles, only Anti-Air, Anti-Tank and Anti-Personnel.

You can check how it works for infantry, it kills everyone in 10-15 meter radius while AT missile does nothing because the HEAT warhead is directed directly ahead where the missile hits.

So, is the current AT actually HEAT?

AP is anti-personnel. Killed once group of eight AI with it from long distance. Very effective.

Yes, all Anti-Tank missiles and rockets are HEAT weapons in game.
APDSFS shells in MBT cannon or autocannon (20mm or creater) use kinetic energy for penetration.

AT is for "Anti-Tank" what means weapon is designed to be used against IFV or MBT (any tracked armored fighting vehicle).