With savings accounts, you can add to and withdraw from them as you please. There can be some restrictions around the interest payable if you make withdrawals, however, you can access the money in the account whenever it suits you. Interest rates on these accounts are generally variable and subject to change at any time.
With term deposits, an amount of your choice (usually a minimum amount of $5,000) is locked away for a set period of time at a fixed interest rate. These rates can often be higher than a standard savings account, however, the money cannot be accessed until the fixed term is over (when the term deposit matures). If you choose to break the term to access the funds early, the interest payments will often be forfeited.