Price - The amount you acquired the bond either directly at par value or from somebody who sold it at a price above or below its par value. When you buy a bond at $800, you would still receive its par value at maturity date the only difference is, your yield is higher.
The total return of the bond until maturity date. Yield is different from the
coupon rate, for instance you bought a $10,000 bond with a coupon rate of 10% its yield is also 10% since you're getting $1,000 yearly from a $10,000 investment. When the price of the bond drops to $9,000, its coupon rate is still 10% derived from its face value of $10,000 but yield is higher, since you're still getting a $1,000 interest from a $9,000 purchase price, your yield is 11% ($1000/$10,000).