0.7: What are Web containers? (brief description)

A Web container handles requests for servlets, JSP files, and other types of server-side include coding. It creates servlet instances, loads and unloads servlets, creates and manages request and response objects, and performs other tasks for managing servlets effectively.

The Web server plug-ins provided by the WebSphere Application Server product help supported Web servers pass servlet requests to Web containers.

"Servlet engine" is an older (Version 3.5.x) name for a Web container, and represents the same functionality.