Jenkins is an open-source, Java-based server that plays a pivotal role in automating the software build, test, and deployment processes, forming a core component of the Continuous Integration/Continuous Delivery (CI/CD) methodology in DevOps. Originating as 'Hudson' in 2004 and later rebranded as Jenkins in 2011, it has grown immensely popular due to its extensive plugin ecosystem, strong community support, and ability to facilitate continuous integration by alerting developers of errors early. Jenkins operates primarily through a Master-Agent architecture, which aids in managing distributed builds across various platforms, and supports pipelines that allow modeling of complex delivery processes as code. It is available for most operating systems and integrates seamlessly with cloud platforms like Amazon EC2 and Google Cloud. Despite its numerous strengths, including being free and highly extensible, Jenkins does have a learning curve due to its feature-driven nature. It remains a favored tool for both startups and large enterprises, offering enhanced release agility and robust CI/CD capabilities.