Linux is a computer operating system that's a free alternative to Microsoft Windows. It runs well on older computers and is 100% file-compatible with Windows (i.e. the same documents, spreadsheets, videos, etc run on both, often using virtually identical software). Replacing Windows with Linux is a possible option for people who will have to ditch their Windows computers this Autumn – this is when Microsoft abandons support for Windows 11 and replaces it with Windows 12, which won't run on many older computers.
Picture by the group leader.