A servlet mapping is a correspondence between a client request and a servlet.
Web containers use URL paths to map client requests to servlets,
and follow the URL path-mapping rules as specified in the Java Servlet specification.
The container uses the URI from the request, minus the context path, as the path to map to a servlet. The container chooses the longest matching available context path from the list of Web applications that it hosts.
Related reference
Web applications: Resources for learning