Every Session is its own browser
Log into the same site on twenty Accounts at once — none of them can see each other.
An Account is a sealed browser Session: its own cookies, storage and cache, on its own partition. Nothing crosses between them, so a login in one Account is invisible to the rest.
Sealed Sessions
Cookies, localStorage, IndexedDB and cache are kept per Account — no shared state to leak.
Its own everything
Downloads and history stay with the Account that made them.
Open in bulk
Launch one Account or a hundred; each is a full browser of its own.