The major difference between VA and FHA loans vs Conventional Loans is that FHA and VA Loans are secured and insured by the Federal Government.  

Conventional Loans are standard mortgage loans that are not insured by the Federal Government.  This means the banks and financial institutions providing these loans take more risk.  For this reason, it takes more to qualify for a Conventional Loan, such as a minimum credit score and a down payment of up to 20%.  Current day Conventional Loans have made loans more obtainable by requesting lower down payments and adding other benefits. 

Most FHA loans make purchasing a home far more accessible, but have way more home buying restrictions than a Conventional Loan.  FHA Loans can be acquired with scores as low as 500 and a down payment of anywhere between 0 and 10%. 

VA Loans are loan products designed specifically for the military and require no down payment and no credit score.