After Adam and Eve sinned agains God by eating from the tree of the knowledge of good and evil God clothed them in His righteousness. This is described in Genesis 3:21:
“The Lord God made for the man and his wife garments of skin, with which he clothed them.”
This indicates that an entire animal was sacrificed so Adam and Eve could be clothed and therefore no longer naked before God.
The burnt offering is an offering of thanksgiving and atonement. It is intended to please God, be a sweet savor, and to cover the offerer in God’s righteousness.
Of course Jesus Christ is our eternal burnt offering since His offering of Himself was pleasing to God and the means of our righteousness.