In the Chart of Accounts you can decide if the account is a P/L account or Balance account. If you click the sum account the account can only be used as collecting a sum and cannot be used for postings. If you click Cash Account the account can be connected to cash holdings such as bank or cash and if Active indicates if the account is active. If not active you cannot post on it.
VAT means that every time you use this account in a posting the VAT is taken and suggested and the account is the account number.