LIBOR stands for London Interbank Offered Rate, which is an interest rate calculated each day based on the rate that international banks lend money to each other on a short-term basis. This rate is used to determine the interest rate on many other loans.
According to USA Today, the LIBOR is used to determine the interest rate on many corporate loans, mortgages and student loans. As the LIBOR rate changes, these loans can become more or less expensive.
LIBOR loans are adjustable rate loans, which means that the interest rate on the loan is periodically adjusted to take into account the change in the LIBOR rate. Most loans have a margin, which is a fixed percentage added to the LIBOR rate to find the interest rate for the loan.
By having an adjustable rate loan tied to the LIBOR, if interest rates drop, the loan rate will drop without you having to refinance. However, if loan rates rise, so too will your interest rate.