What exactly is Jass?

I'm not 100% sure if this is the right forum, but here we go.

When we speak about Jass, we talk about the language Warcraft III uses. The language behind GUI.
But in the blizzard.j file, it is defined that Jass2 is the language of Warcraft III so here comes my question "What exactly is Jass"?

I understand that Jass was rendered by the trigger editor of StarEdit, but it didn't gave you the flexibility of creating your very own Jass triggers without external tools.

Is this information correct?
Do we have proof that this is actually Jass, or is this just an assumption based on logic?

I think that "JASS" is the programming language used in RoC. But I'm not entirely sure.

Jass is the scripting interface for Warcraft 3 maps.

The blizzard.j inside the MPQ of RoC also defines Jass2 as the language Warcraft III uses.

According to the blizzard.j file, that is Jass2.
But what about Jass1, actually just Jass.

No idea, it was likely the scripting language in SC, or maybe an early version of WC3 if it was ever re-written during the development. Nobody cares, we just call Jass2 Jass.

WHAT?! Jass is actually Jass2?! My life is ruined!

It is indeed so.
Jass 1 was used in SC.

But do we have proof of this, or is this an assumption based on logic?
I never really owned a copy of Starcraft and I began editing in Warcraft III.
I just find it interesting to know a little history of things sometimes, that's why I dug in this a little.
But all I found were statements pretty much just like yours, not real proof that it is so.

I don't have to see the proof to believe it, but I'd like to know if there are any.

Starcraft you could only trigger in GUI, but there was actual code derived from that when you saved the map^{[citation needed]}.

Nope. It's actually A.S.S2:
j-Asynchronous Scripting Syntax 2

Seems to me like blizzard threw the J in to prevent bad jokes .