You can use the Registers screen to view transactions and their details for an account. The account balance displayed there is determined by the transactions listed and does not show the running balance for the account from all transactions.
In Core, the account register only shows the transactions and running balance for the period selected. If you want it to show the running balance from the inception of the account, you should select All Dates in the Period drop-down. Core then displays all the transactions for the account and the overall running balance.
You can also see the overall running balance of an account from the Chart of Accounts screen under the Balance column for that account. Or you can run the General Ledger report for that account without using any date filters to see the running balance from all transactions. Check the Core Help for details.