Philosophy of science is a branch of philosophy that reflects, radically and integral about the nature of knowledge itself. This writing aims to understand: (1) understanding of knowledge and science in etymology and terminology. (2) the difference of science, knowledge and religion in epistimology. (3) the extent of science in Islam. (4) the basic characteristics of science. (5) truth theory. (6) sources of knowledge. (7) the boundaries of science (8) the structure of knowledge. The results of this paper are: (1) science is from Arabic, 'alima. The meaning of this word is knowledge. And science in terminology is the whole conscious effort to investigate, find, and improve human understanding from various aspects of reality in human nature ...