Difference Between Kingdom of God and Heaven

(Matthew 13:44 KJV) Again, the kingdom of heaven is like unto treasure hid in a field; the which when a man hath found, he hideth, and for joy thereof goeth and selleth all that he hath, and buyeth that field.
(Romans 14:17 KJV) For the kingdom of God is not meat and drink; but righteousness, and peace, and joy in the Holy Ghost.