if the user types "hi" respond with "hi" or "bye" or "..." you get the point. It's basically storing the most probably following words (tokens) given the current point and its history.
That's not a brain and it's not thinking. It's similar to JIRA because it's stored information and there are if statements (admins can do this, users can do that).
Yes it is more complex, but it's nowhere near the complexity of the human or bird brain that does not use clocks, does not have "turing machines inside", or any of the other complete junk other people posted in this thread.
The information in Jira is just less complex, but it's in the same vein of the data in an LLM, just 10^100 times more complex. Just because something is complex does not mean it thinks.