Thread: Is there a process()-like method in a client? and what do packets do?

I am trying to get an item's name to change as a player enters a certain area, but i figure it needs to use a process that tells the item's name to change whenever their coordinates are within the vacinity.

And also, what do packets do? Are they a way for the client to communicate with the server? What can I use it for? How do I use it?