This manual, the fruit of a great deal of research and in line with the national ICT syllabus and the consequent innovations that followed, is also the answer to the needs expressed by 4th year finalists in the Humanités Scientifiques course, according to the new competency-based approach (APC) reform in the Democratic Republic of Congo. In this marvelous manual, written in a simple yet profound and rich style, the author has revealed all the essential knowledge on computer networks, network architecture, social networks, computer security and artificial intelligence. In this way, each chapter is explored in minute detail to help learners assimilate the material and assess their own progress. Since 2007, the author has been teaching Mathematics and Computer Science in both public and private schools in the Democratic Republic of Congo. He is very enthusiastic about writing computer manuals among many others to improve the teaching of this course and serve the teaching and Congolese community.