This chapter presents an introduction to WebSphere security by taking the reader to a tour that helps him observe the environment from three different angles. Each of the views presented in a way supplements the other two. Aspects related to security are at the center of each of the views described. In this chapter and in the remaining part of the book experienced users will get acquainted with new security aspects offered by the IBM WebSphere Application Server Network Deployment version 7.0. In addition, and perhaps more importantly, the material covered in this chapter and the rest of the book is presented so no prior knowledge of WebSphere security (as in earlier versions of WebSphere) is required. This fact makes it easier for new WebSphere administrators to learn the security aspects of WebSphere version 7.0. Throughout the rest of the book, the terms WebSphere Application Server Network Deployment version 7 and WAS ND7 will be used interchangeably. Let's get started!