Our aim in writing this book for fourth-year Humanities Science students is to support the national curriculum for this option, which is rich in Information and Communication Technologies (ICT). In this book, we have developed related notions on computer networks, social networks, client-server systems, artificial intelligence and other notions oriented towards different algorithms. The book is based on the national curriculum for the year 2021.It should also be pointed out that this book has been written with a great deal of courage and love, in order to raise the level of knowledge of our science option students and bring up to date our ICT teachers who have not been able to tackle their computer studies up to degree level.