General and special revelation are the two ways God chooses to reveal Himself to humankind.
General revelation (also called natural revelation) is God’s revealing of Himself through creation.
The heavens declare the glory of God;
the skies proclaim the work of his hands.
Day after day they pour forth speech;
night after night they reveal knowledge.
Psalm 19:1-2 (NIV, emphasis added)
For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that people are without excuse.
Romans 1:20 (NIV, emphasis added)
The order, splendor, and intricate design of the universe, earth, and human body all point to a Creator, Yahweh.
Special (or Supernatural) revelation refers to the deeper revealing of God through miraculous means. These include things like: God physically walking on earth (as in Eden) or showing up as a burning bush or a mysterious man wrestling with Jacob; God speaking to people audibly or in visions; angelic visitations; through the words of prophets; in miracles; and through Jesus Christ, the Holy Spirit, and Scripture.
Even with a knowledge that there is a God, we still need the special revelation of God’s character, His promises, purposes, and perfect plan of redemption for humanity.