Abstract " The Effect Of The Developed (K.W.L.N) Strategy Supported By Digital Applications On Cognitive Achievement And The Performance Of Some Defensive Skills In Volleyball" * Dr. Manar Mahmoud Abdel Salam Shaaban  The researcher conducted a study entitled “The impact of the developed (K.W.L.N) strategy supported by digital applications on cognitive achievement and the performance of some defensive skills in volleyball.” The research aims to design an educational program using the developed (K.W.L.N) strategy supported by digital applications and its impact on cognitive achievement and the performance of some defensive skills in volleyball. Volleyball for students of the Faculty of Physical Education for Girls - Zagazig University by identifying: the impact of the developed (K.W.L.N) strategy supported by digital applications on the cognitive achievement of fourth-year female students majoring in volleyball., And the impact of the developed (K.W.L.N) strategy supported by digital applications on the skill and technical performance of some defensive skills (receiving with the forearms - defensive blocking wall - defending the court with the hands while standing) in volleyball for fourth-year female students specializing in volleyball. The researcher used the experimental method by conducting (pre-test) measurements. - Dimensional) for one experimental group. The research population was chosen. The research population consists of female students in the fourth year - majoring in volleyball, for the academic year (2023/2024 AD), numbering (114) female students. The research sample represents (36) female students who were chosen intentionally They represent the basic research sample (the experimental group), in addition to a group of (20) female students for the exploratory study from within the community, and outside the basic sample, to calculate the validity and reliability coefficients for the tools under research. The most important conclusions reached by the researcher indicated - the impact of the strategy program (K.W.L.N) The developed program supported by digital applications is suggested positively on the variables (cognitive achievement) of the experimental group. - The developed (K.W.L.N) strategy program supported by digital applications has a positive effect on skill and technical performances (receiving with the forearms - defensive blocking wall - defending the field with the hands from standing). - There are percentages Improvement between the two measurements (pre and post) in the variables under study(Cognitive achievement - skill and artistic performances) for the benefit of dimensional measurement. The researcher recommends applying the developed (K.W.L.N) strategy supported by digital applications to the various learning outcomes. - Applying the developed (K.W.L.N) strategy supported by digital applications in developing the skill and technical performances of volleyball..