Common Grace: I believe I first learned the term "Common Grace" from Presbyterian brothers who collect all the Scriptures pertaining to God's love & blessings for the common unregenerate man under this heading.
"He sends His rain on the just and the unjust..." etc.
Special Grace: And this is the term employed to refer to all those Scriptures that speak of God's love & blessings reserved strictly for those who are in Christ.
"If any man keep my sayings, my Father will love him...." etc.
Universalism: The cancerous doctrine that actively ignores the distinction between the above two.