What can I do with the Ask / Search bar?

The bar does three things at once. Type a few words to instantly filter the site's content; type a destination to jump straight there; or ask a full question and the concierge answers in plain language, grounded only in what's actually on the site, with the sources it checked shown beneath the answer. Open it from the floating button, the homepage box, or with Cmd-K / Ctrl-K.