Glossary
.logarchive
A portable macOS bundle holding a copy of the Unified Log store: tracev3 files, uuidtext and dsc strings, and timesync records.
A .logarchive is a folder (shown as a single package in Finder) created by log collect or included in a sysdiagnose. It contains the Persist, Special, Signpost and HighVolume tracev3 folders, timesync, the uuidtext folders and dsc, an Info.plist, and logdata.LiveData.tracev3 with the in-memory buffer at collection time.
Because it is self-contained, it can be read later with log show --archive or cross-platform parsers. Some file pickers cannot select a package: drag it or zip it. See how to collect Unified Logs.