Many new testers often ask: what is coverage in testing and why do so many teams track it? In simple terms, coverage is a metric that shows how much of your application’s functionality or codebase has been exercised by your test cases. It comes in different forms:

Code coverage → Measures which lines, branches, or conditions in the source code are executed during testing.

Requirements coverage → Ensures every documented requirement has at least one test case mapped to it.

Path or decision coverage → Focuses on testing logical paths and decision-making branches in the application.

Coverage matters because it helps identify gaps in your testing strategy. For example, you may have 80% code coverage but only 50% requirements coverage, meaning your tests are not aligned with actual business needs. On the other hand, chasing 100% coverage can sometimes be misleading if tests are superficial and don’t check real-world scenarios.

In practice, coverage is most useful as a guidance metric—it highlights where you need more tests but should be paired with qualitative approaches like exploratory testing, edge case analysis, and real user simulations.
Learn more about code coverage and it's importance in software testing here:
https://keploy.io/blog/community/understanding-code-coverage-in-software-testing