Savings accounts usually don't come with a debit card like everyday transaction accounts, so you can withdraw money from the account at ATMs.
To access the money in your savings account, simply transfer your money from your savings to your linked everyday account using your mobile banking app or via Internet banking. If you've got your bank account and savings account with the same bank (this is a good idea!), the money will be transferred instantly which you can then access with your debit card.
Keep in mind that, depending on the savings account you choose, there may be restrictions as to how often you can withdraw from the account before you forfeit your bonus interest. If you know you want to lock away your funds for a longer period, you may want to consider a term deposit instead of a savings account.