A new position that involves revisiting/ revising the terms of an existing finance (e.g., a loan, credit facility, a mortgage loan, etc.) including interest rates, payment schedules, maturity date, etc. Typically, and with everything else held constant, borrowers opt for refinance when market rates fall. Refinancing is not automatic or hassle-free, as in most cases it involves updating creditworthiness and repayment status of a borrower.

In terms of the pros, a borrower with a mortgage loan may get one or a host of benefits from refinancing including a lower interest rate, a smaller monthly payment,  a shorter repayment term, etc.