i have a question regarding textarea, i wan the user input in a textarea to be display across all other textarea on my site

pls someone help me with my question

It depends what you mean. On the face of it, if someone types "Fred Smith" in the "Name" box, you want "Fred Smith" to appear in the phone number box too? That could happen in the browser, using javascript.

But doesn't sound very likely. Perhaps you want to save some text for each user, and just display it back to this user? (What on earth for?) In which case you could save it in a cookie.

Or perhaps you want some info to become available to all users? In which case you need some sort of server script and database.