This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Every web application has exactly ONE instance of javax.servlet.ServletContext ... according to java's specification.
Each servlet has its own ServletConfig object. In other words, there is 1 ServletConfig object for each servlet. Think of ServletConfig as a wrapper around servlet's initialization parameters that are passed into the servlet for its instantiation.