Summability theory is originally based on classical analytic method, but is strongly influenced by modern functional analytic method. Functional analysis approach to summability has greatly influenced the various applications of summability in, for example, approximation theory. The current development in the subject is further encouraging the students and researchers to have some new findings in this subject.

H. K. Nigam, Ph.D. (Mathematics): Harcourt Butler Technological Institute, Kanpur, India. Associate Professor of Mathematics in Department of Science and Humanities at Faculty of Engineering and Technology, Mody Institute of Technology and Science Lakshmangarh, Sikar, India.