The two terms get used interchangeably, but they mean different things to a seller reviewing your offer.
A quick, informal estimate based on self-reported income, debt and credit information. Useful for an early sense of your range, but it doesn't verify anything and carries little weight with sellers.
A more formal process where a lender verifies your income, assets and credit, and issues a conditional commitment for a specific loan amount. This is what real estate agents and sellers expect to see attached to a competitive offer.
In a competitive Denver market, a prequalification letter alone often isn't enough to compete. Getting fully preapproved before you start touring homes means you can move quickly — and negotiate more confidently — when you find the right property.