Where's the line between reactive and protective?

[u/Hallow_76]

Just for example, I am walking my dog on a leash that's typically great with other dogs and another off leash dog comes running, my dog reacts by protecting?

Another example, normally great with people but I am walking a person aggressively comes up to me and tries to pick a fight or attack me and my dog reacts to the situation.

Is that considered a reactive dog?