I tried to read Monero guide, but I didn't understand some things.

I have 4wzx, 8AAA, 8sgs in Accounts and 8AAA, 8gjm in Receive. Why 8AAA and 8AAA are same, but 8sgs and 8gjm are different? To which adress will belong money, if someone send monero to 8gjm-subadress?

Can I send money to to Accounts-subadress & adress? Or maybe I should use only Receive-subadresses? 

What's the difference between purpose of Accounts-subadresses and Receive-subadresses?

Thanks.