Parshat Vayakhel begins with a very interesting verb - "Moshe gathered Am Yisrael" - why does the Torah need to tell us that Moshe gathered Am Yisrael?

Can't we assume that they were gathered - like every other time Moshe spoke to them?

What is the meaning of this "gathering?"

And why is so important now to "gather" Am Yisrael?

And what are communities about?