> For the complete documentation index, see [llms.txt](https://www.adblocklabs.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.adblocklabs.com/docs/core-concepts.md).

# Core concepts

- [What is HTTPS filtering](https://www.adblocklabs.com/docs/core-concepts/what-is-https-filtering.md): Why AdBlock needs to look inside HTTPS traffic, how it works under the hood, and how we keep your connection safe.
- [System-level vs. browser ad blockers: what's the difference?](https://www.adblocklabs.com/docs/core-concepts/system-level-vs.-browser-ad-blockers-whats-the-difference.md): Differences between system-level and browser extension based Ad Blockers