S&P 500, VUSA vs VUAA

What is the difference between VUSA and VUAA?

I want my dividends to be automatically reinvested into the fund, do they both do that or not?

VUSA has (dist) VUAA has (acc)

What do these mean?

Thank you, I am trying to wrap my head around this as I am new to this.

Other tips and advice is also welcomed and appreciated.