There are at the minimum two types of home equity loans.
The first is a term or closed end loan and the second is basically a line of credit. Most people prefer to refer to them as a second mortgage because they are secured against your home much like your first home loan or mortgage. Typically these types of home equity loans usually have a payback life of between 5 and 15 years.
The term loan is a one-time lump sum payment that is paid off over a set amount of time. There is a fixed interest rate which allows for the same loan repayment each month. After you get your money you cannot borrow further from the loan.
A home equity loan line of credit works more like a credit card. You are allowed to borrow up to a certain amount for the life of the loan. The time limit is usually set by the lender of the loan. During that time you can withdraw money as you require it to buy items or pay for things that interest you. As you pay off the principal your credit revolves and you can use it again. This credit line gives you more flexibility than a term home equity loan.
Which ever of the two types of home equity loans that you should use depends on your rare situation. You can base your decision on some shared questions such as how much money will you need, how long will you need the money for, how long will you need to pay the loan off and how much of a monthly payment can you provide.