Quick meaning
A message in a chat that is marked as important so it stays visible at the top, even as new messages come in.
Think of it like this
Like tacking an important notice on a bulletin board above all the other notices.
Where you may see this
You may hear this in email apps, messaging apps, video calls, and workplace instructions.
Why it matters
Knowing the term makes it easier to message people correctly and avoid simple communication mistakes.
Say it simply
Pinned Message means: A message in a chat that is marked as important so it stays visible at the top, even as new messages come in.