Knowledge is a familiarity, awareness, or understanding of someone or something, such as facts, information, descriptions, or skills, which is acquired through experience or education by perceiving, discovering, or learning.
Knowledge is of two kinds. We know a subject ourselves, or we know where we can find information upon it.
Samuel Johnson, reported in James Boswell, Life of Samuel Johnson (1775). Quote reported in Hoyt's New Cyclopedia Of Practical Quotations (1922), p. 419-23.