A “conventional” mortgage is one that is not insured by the federal government. An FHA loan is insured by the government. FHA loans usually have lower down-payment requirements, when compared to conventional mortgages. This is one of the key differences between them. It also accounts for their popularity among first-time home buyers.
The FHA does not actually lend you the money. This is a common misconception. You would still get the money from a regular lender, as with a conventional loan. The difference is the insurance provided by the government. The Federal Housing Administration guarantees the loan, so the lender is covered if the borrower defaults on the loan. This reduces the lender’s risk. This is also why the down payment for an FHA loan is generally lower than a conventional mortgage.