This document discusses distributed tracing and provides an overview of its history and key concepts. It begins with an overview of logging, tracing, and monitoring techniques. It then discusses the challenges of debugging asynchronous distributed systems and how distributed tracing addresses these challenges. The document outlines the basic terminology and components of distributed tracing systems, including spans and traces. It provides a timeline of major developments in distributed tracing technologies from 2010 to the present. It concludes with recommendations around using OpenTelemetry or OpenTracing for instrumentation and notes areas that were not covered in depth.