# Explainer: macOS updates – The Eclectic Light Company

<https://eclecticlight.co/2026/02/28/explainer-macos-updates/>

- Host: [eclecticlight.co](https://links.thingelstad.xyz/hosts/eclecticlight.co/)
- Saved: March 3, 2026 (2026-03-04T01:42:58Z)
- Record: https://links.thingelstad.xyz/links/e365039f0a47/
- JSON: https://links.thingelstad.xyz/links/e365039f0a47.json

## What Jamie wrote

Deep technical explainer on how macOS updates work — from old Installer packages through Catalina's split volumes to Big Sur's Signed System Volume. Good reference if you've ever wondered what's actually happening during updates.\n\nPull quote: "Big Sur brought the greatest structural change in Mac operating systems since the introduction of Mac OS X twenty years earlier."

## Facts

- Kind: [Page](https://links.thingelstad.xyz/kinds/page/)

## Same host

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- [Last Year on My Mac: Look back in disbelief – The Eclectic Light Company](https://links.thingelstad.xyz/links/92f0ea2e6983/) (eclecticlight.co, January 8, 2026)

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## Elsewhere

- Wayback Machine: https://web.archive.org/web/*/https://eclecticlight.co/2026/02/28/explainer-macos-updates/