This is a summary of OpenTelemetry metrics in 1 paragraph. OpenTelemetry is an open-source observability framework that simplifies the process of collecting signals from services and sending them to the backend of choice. It provides six instrument types: counters, asynchronous counters, UpDownCounters, asynchronous UpDownCounters, histograms, and asynchronous gauges. Each type has its own characteristics and use cases, such as synchronous vs asynchronous implementation, aggregation types, and attributes attachment methods. OpenTelemetry aims to define a single standard across all types of observability data, including metrics, logs, and traces. It provides a Collector that can be used to reaggregate and redirect metric data, and a global MeterProvider that creates a Meter and associates it with one or more Instruments. The framework allows for flexible transformation in the collection path, supporting multiple export types, including push and pull options. This enables interoperability between existing metric systems, making OpenTelemetry an attractive option for developers looking to standardize their observability data.