1、一个tomcat可以配置多个host；
2、一个host可以包含多个应用：context；
3、一个应用可以包含多个servlet：servlet-path;
4、一个servlet可以包含多个request：request-path;
Tomcat’s Architecture
Tomcat’s architecture consists of a series of functional components that can be combined according to well-defined rules.
Tomcat Architecture
The structure of each server installation (via these functional components) is defined in the file server.xml, which is located in the /conf subdirectory of Tomcat’s installation folder. Let’s discuss these components in detail.
https://howtodoinjava.com/tomcat/tomcats-architecture-and-server-xml-configuration-tutorial/
web.xmlの定義
URLパスよって呼び出されるサーブレットクラスの場所は次の図の通りである。また、URLパスとサーブレットのマッピングはweb.xmlに定義されている。
https://eng-entrance.com/servlet-web-xml
https://www.ntu.edu.sg/home/ehchua/programming/java/JavaServlets.html