The libor rate - London InterBank Offered Rate - is a particular type of that applies to the banks in London.
It is the average of rates under which the major London banks are willing to borrow funds, and is the benchmark rate for setting interest rates in various interest rate contracts.
It applies to 5 currencies and 7 borrowing periods ranging from overnight to one year.
It is calculated by the Intercontinental Exchange (ICE) and published by Thomson Reuters.
The exact calculation is based on the daily responses of a certain number of banks (for example 18 banks in the USD case) just before 11 am.
Then some of the highest and lowest responses are thrown and the average is calculated and reported out of the remaining rates.