Technological Pedagogical Content Knowledge (TPACK) is a framework for teaching effectively that has three requirements. As well as the need for knowledge of the subject matter and of pedagogy, it argues for an understanding of technology.
For more information, a good place to start is this site: http://tpack.org
Koehler, M. J., & Mishra, P. (2009). What is technological pedagogical content knowledge? Contemporary Issues in Technology and Teacher Education, 9(1), 60-70.
Mishra, P., & Koehler, M. J. (2006). Technological Pedagogical Content Knowledge: A framework for teacher knowledge. Teachers College Record, 108(6), 1017-1054. doi: 10.1111/j.1467-9620.2006.00684.x.
Shulman, L.S. (1986). Those who understand: Knowledge growth in teaching. Educational Researcher, 15(2), 4-14.
TPACK diagram Reproduced by permission of the publisher, © 2012 by tpack.org