<human>: What's the difference between a mortgage and an ARM?
<bot>: The primary difference between a mortgage and an adjustable-rate mortgage (ARM) is that with a mortgage, the interest rate remains fixed for the entire loan term, while an ARM typically has an initial fixed interest rate for a set period of time, followed by an adjustment in the interest rate after that. Additionally, mortgages usually have higher closing costs than ARMs, which can make them more expensive overall.