Mac storage basics · Finding big files, Downloads and the Trash
What are .DS_Store and ._ files on my drives?
Short answer: .DS_Store files save Finder view settings; ._ files store Mac-specific attributes on Windows-format drives. Both are tiny; deleting ._ files can drop things like Finder tags.
.DS_Store files hold Finder's view settings for a folder (icon positions, sort order). ._ files appear on drives formatted for Windows (such as exFAT) and store Mac-specific information, like extended attributes, that those formats can't hold natively.
Both are tiny and safe to ignore. Deleting ._ files from an exFAT drive can remove Mac-specific details such as Finder tags for those files.