This article describes a framework for teacher knowledge for technology integration called technological pedagogical content knowledge (TPACK). The development of TPACK by teachers is critical to effective teaching with technology. The TPACK framework for teacher knowledge is described in detail, as a complex interaction among three bodies of knowledge: Content, pedagogy, and technology. The interaction of these bodies of knowledge, both theoretically and in practice, produces the types of flexible knowledge needed to successfully integrate technology use into teaching.