一个Servlet容器是一个必须能够运行Java Servlet的Web服务器.

A Servlet Container is a Web Server that must be able to run Java Servlets.

Web服务器是一个广义的术语，包括所有通过HTTP协议运行和通信的软件.

Web Server, on the other hand, is a broader term including all software running and communicating through HTTP protocol.

在以下定义下:

1. 所有Servlet容器都是 Web服务器
2. 并非所有的Web服务器都是 Servlet容器. IE. Apache HTTP Server无法直接运行Java Servlet.

1. All Servlet Containers are Web Servers
2. Not all Web Servers are Servlet Containers. I.E. Apache HTTP Server can not run Java Servlet directly.