Apache Tomcat (or simply Tomcat) is an open source servlet container developed by the Apache Software Foundation (ASF). Tomcat implements the Java Servlet and the JavaServer Pages (JSP) specifications from Oracle Corporation, and provides a "pure Java" HTTP web server environment for Java code to run.
Once the environment is created, you can click Open in browser button next to the Tomcat server in the environment (expand the environment in the Environments pane at the top of the screen).