pleeaase!
The advantage is that you know that you will receive a set rate of return at the end of the term. You know that you are guaranteed a certain interest rate. They are a secure investment in Australian banks, even more so now that the Federal govt has guaranteed their security. If interest rates fall, you are guaranted the rate at which the investment was made.
Disadvantages: If interest rates go up, you may be locked in at a lower rate. The funds are not at call, they are locked into a contract for a certain term agreed by you and the bank.
Most organisations will arrange to break the term in an emergency, however interest penalties may apply.
I look at it like a CD/bond/note.
Advantages: High interest rates compare to normal savings/checking account.
Disadvantage: You are locked in with that deposit for a certain time agreed upon.
Advantages - You earn more money without touching it,
Disadvantages - You cant touch it.