In Vietnam, since 1615, with the presence of missionary Francesco Buzomi in Hoi An, Catholicism has been around for nearly 400 years. The process of Catholic missionary development in Vietnam has obtained certain results. Currently, the Vietnamese Catholic community has 7.2 million believers distributed over 27 dioceses of the whole territory of Vietnam, not to mention the community of millions of overseas Vietnamese Catholics. The Vatican is taking appropriate steps to gradually improve diplomacy so that they can move towards fully establishing diplomacy with Vietnam. More and more Vietnamese people (either believers or not) have the need to learn about world Catholicism and Catholicism in Vietnam. This book provides readers with the basics of Catholicism, especially in Vietnam, through selected reliable sources.