Questions about tty

1. Why are there so many ttys? Are multiple tty necessary? 2. Why are multiple things spread in different ttys? For eg i have the runit logs on tty1, wm on tty7, and a blinking white cursor on the corner of screen on tty8. Why not everything in one tty? 3. Why doesn't linux place these in order - tty1: runit logs, tty2: wm, etc. 4. What does the binking cursor mean?