Prometheus is an open-source monitoring and observability tool that can collect data using HTTP pulls or pushes, focusing on metrics collection. It supports a multi-dimensional data model and has a pull-based data collection approach. Prometheus originated as a project inside SoundCloud in 2012 and gained popularity for monitoring cloud-native applications. In contrast, Datadog is a commercial product that offers a broader range of capabilities, including full support for collecting and analyzing logs, metrics, and traces. Datadog provides a push-based model for data collection and has built-in features like Metrics Explorer, RUM Explorer, and Log Explorer for data analysis and interpretation. Prometheus requires more configuration options and is free to operate, but it lacks some of the advanced features offered by Datadog. The choice between Prometheus and Datadog depends on factors such as cost, ease of use, deployment flexibility, and specific use cases. Groundcover is an alternative that offers the flexibility of Prometheus combined with the advanced features of Datadog.