Meaning
A small triangle pointing up, usually inside a square button. It means up: move higher, scroll up or look at what is above.
People use it to point at an earlier message or the post above, to show something rising, or as a tidy bullet in lists: “Answer’s in the message 🔼” In group chats it is a polite nudge to read back. For a big jump to the very top, ⏫ or 🔝 work better.