Most conventional mortgages have a fixed rate, which means that the interest will stay the same for the lifetime of the loan. With a fixed-rate mortgage, the home buyer will know exactly what the interest payments will be at the time the loan is signed, and they will never have to contend with fluctuating loan payments.
A fixed-rate loan lets you plan your finances exactly, because you will always know what your monthly payments will be. Depending on the conditions of the market at the time, an adjustable rate mortgage might seem to have a payment advantage over fixed-rate mortgages in the initial stages of the loan. However, those payments could easily go up over time in an unpredictable manner.
A fixed rate conventional loan may be a good choice for someone who has excellent credit and enough money for a substantial down payment. This is particularly good for a home buyer who is looking for some kind of stability, so they can plan for their payments and budget accordingly.