Observability vs. Logging vs. Monitoring

Imagine a developer working on the checkout flow of an e-commerce application. A few hours after the feature goes live, a user reports the following error:

In modern AWS architectures, especially those built with microservices and serverless, we need complete visibility into the system to troubleshoot effectively. This is where the three concepts—logging, monitoring, and observability—become essential. Although they are related, each serves a different purpose.

What is logging?

Let’s begin with logging. Imagine a user reporting a problem. To understand what went wrong, the developer needs a historical record of events during that transaction. Logs provide this.

Logging is the first and most fundamental layer of visibility, acting like a record book that captures events, errors, and status updates. It’s the simplest way an application communicates what it’s doing. For example, while writing code, developers often include error messages or other log entries so they can later trace issues and understand the context in which they occurred.

Logging gives us a time-stamped history of events. We’re ...