This is a lecture note series edited by A. Dold and B. Eckmann, published by Springer-Verlag. The series is part of the Université de Nice, Faculté des Sciences. The book titled "Théorie des Topos et Cohomologie Étale des Schémas" is Volume 2 of the SGA 4 seminar, held in 1963-1964. The seminar was directed by M. Artin, A. Grothendieck, and J.L. Verdier, with collaboration from N. Bourbaki, P. Deligne, and B. Saint-Donat. The content includes eight exposés, covering topics such as cohomology in topoi, descent techniques, finiteness conditions, fibered sites, and cohomological study of finite morphisms. The book also includes a terminology index and a notation index. The work is protected by copyright and requires payment for reproduction or distribution outside private use. The AMS subject classifications are 14–02, 14Dxx, 14F20, and 14E20. The ISBNs are 3-540-06012-X and 0-387-06012-X. The seminar is part of the Séminaire de Géométrie Algébrique du Bois-Marie, a series of algebraic geometry seminars held at the Bois-Marie research center. The content is written in French, with English summaries provided for the exposés.This is a lecture note series edited by A. Dold and B. Eckmann, published by Springer-Verlag. The series is part of the Université de Nice, Faculté des Sciences. The book titled "Théorie des Topos et Cohomologie Étale des Schémas" is Volume 2 of the SGA 4 seminar, held in 1963-1964. The seminar was directed by M. Artin, A. Grothendieck, and J.L. Verdier, with collaboration from N. Bourbaki, P. Deligne, and B. Saint-Donat. The content includes eight exposés, covering topics such as cohomology in topoi, descent techniques, finiteness conditions, fibered sites, and cohomological study of finite morphisms. The book also includes a terminology index and a notation index. The work is protected by copyright and requires payment for reproduction or distribution outside private use. The AMS subject classifications are 14–02, 14Dxx, 14F20, and 14E20. The ISBNs are 3-540-06012-X and 0-387-06012-X. The seminar is part of the Séminaire de Géométrie Algébrique du Bois-Marie, a series of algebraic geometry seminars held at the Bois-Marie research center. The content is written in French, with English summaries provided for the exposés.