GitHub GH-900 glossary of repository, collaboration, permissions, and workflow terms.
Use this glossary when GitHub Foundations (Foundations) terms start to blur together. The goal is practical recognition, not encyclopedia coverage.
| Term | Exam meaning |
|---|---|
| Commit | Snapshot of changes in Git history. |
| Branch | Movable line of development in Git. |
| Pull request | GitHub workflow for proposing, reviewing, and merging changes. |
| Status check | Automated signal that reports whether a commit passed a required process. |
| Repository secret | Encrypted value made available to workflows without storing it in code. |
| Branch protection | Rule set controlling how changes can be merged into a branch. |
| Pair | How to separate them |
|---|---|
| Git and repositories vs Pull requests and reviews | Ask which layer the scenario is testing, then match the answer to that layer only. |
| Control vs evidence | A control changes behavior; evidence proves behavior or supports investigation. |
| Managed service vs custom build | Managed services win for lower operational effort unless the requirement needs unsupported customization. |
| Prevention vs detection | Prevention blocks or reduces a bad event; detection finds or reports that it happened. |
Do not memorize terms in isolation. For each term, write one scenario where it is the best answer, one scenario where it is a distractor, and one signal that proves it worked.