Prometheus is an open-source monitoring system widely used in DevOps for processing time series metric data, favored for its extensive integration capabilities with other tools and systems, including Docker and Kubernetes. It uses exporters to facilitate data communication and has a large community of contributors. Prometheus collects, organizes, and stores metrics with unique identifiers and timestamps, allowing developers to query and visualize data through PromQL and Grafana. This tutorial provides a foundational guide to setting up Prometheus on local environments and Docker, detailing the installation of Prometheus, Node Exporter, and cAdvisor, and configuring the prometheus.yml file for system and container monitoring. The text also highlights the necessity of using cAdvisor for Docker metrics and addresses common configuration challenges such as port conflicts.