whats the difference between the = block and the is identical? blocks?

I've done many tests and so far, I haven't found a difference between the two blocks, <[] = []> and <is [] identical to []?>, so, what's the difference?

Here's an example that reports differently for = and is identical:

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These are not the same list, but they're equivalent.

In other words, < is [ ] identical to [ ] ? > reports true if the two entities are the same object, not just if they are equivalent.

... Following up on that:

The reason it matters is that if two equal list values are identical, then changing one of them (with INSERT, ADD, DELETE, or REPLACE) changes the other, too; if not, not.

never tried that before, thanks