Normal CoA is coating and imbuing your own body in CoA.
Advanced CoA has two forms:
1) Emission. This allows you to imbue CoA into things that are outside your body. Like flying slashes, any projectiles, etc. It can also allow you to create invisible haki barriers outside your body to attack/defend with, such as Sentomaru did vs Luffy pre-skip.
2) Internal Destruction. This is second step of Emission. This time around, you don't just emit CoA outside your body, you directly transfer it in a destructive manner into someone else's body, dealing damage to their insides.
For example, Luffy's Red Roc is Internal Destruction CoA. Zoro imbuing CoA into his flying slashes and creating barrier vs Hakai in 1009 is Emission CoA.
I think Sanji can technicallllyy imbue his own flames in CoA, effectively increasing their potency and turning them black, by using Emission. Idk. It's just a theory, we've not seen anyone apply CoA to something like fire yet, though.