God's revelation refers to the ways in which God has chosen to disclose Himself, His Word and His will to humanity. This concept is foundational to understanding the nature of God, His purposes, and His interactions with the world. Revelation is generally categorized into two types: general revelation and special revelation.

General revelation is the knowledge of God and His attributes that can be discerned through nature, history, and human conscience. It is accessible to all people, regardless of their religious background. The Apostle Paul speaks of this in Romans 1:20.

Romans 1:20

For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse:

Special revelation is something that happens between God and man.  It is God  speaking (or revealing something) to a person whether it be through an agent such as Jesus or an angel or a dream or a vision.  Any of these would be considered a type of special revelation from God.

Special revelation refers to God's specific communications and manifestations to particular individuals or groups, which are not accessible through general revelation. This includes the Scriptures, the person of Jesus Christ, and other direct communications from God.  

Gal. 1:11-12

[11] But I certify you, brethren, that the gospel which was preached of me is not after man.
[12] For I neither received it of man, neither was I taught it, but by the revelation of Jesus Christ.