4. How does Jenkins work?
Jenkins is available as a WAR archive, installation packages for major OS systems, Homebrew packages, Docker images, and source code. The source code is largely Java, with some Groovy, Ruby, and Antlr files thrown in for good measure.
The Jenkins WAR can be executed as a standalone application or as a servlet in a Java application server like Tomcat. It generates a web user interface in either instance and takes requests to its REST API.
Jenkins creates an admin user with a random password when users run it for the first time, which users may paste into the installation's initial webpage to unlock it.
