Does not show the Pi_AP Network when we connect to the Pi. What does that mean?

Does not show the Pi_AP Network when we connect to the Pi. What does that mean?

Step-1
Check if any tablet is showing the network.

Step-2
Restart the Pi.

Step-3
Restart the Tablets.

If problem still persists, Change the SD card of Pi and try again if still problem didn't get resolved Change the Pi.