Prometheus is an open-source monitoring and alerting toolkit that offers a multidimensional data model, efficient data storage, and querying capabilities through its powerful query language, PromQL. It scrapes metrics from instrumented targets using the HTTP pull model and provides a flexible and powerful alerting system to send notifications based on predefined rules and conditions. Prometheus seamlessly integrates with Grafana for visualization and is suitable for traditional server-based architectures and cloud-native environments. OpenTelemetry is an open-source project focused on standardizing the collection of distributed traces and metrics in modern cloud-native applications. It provides a vendor-agnostic approach to observability, facilitating distributed tracing, instrumentation libraries, pluggable architecture, context propagation, and seamless integration with different observability backends. OpenTelemetry excels in scenarios where distributed tracing is critical for understanding interactions between different components, making it an ideal choice for complex, cloud-native applications with multiple microservices and service-to-service communication.