Public IPs allow you to assign a static IP address to let your VMs and load balancers be accessible from the Internet.
For finding out your public IPs go to the “Networking” blade and select “Public IPs”:
Here you can find out IP addresses which you use.
You can detach them or delete them.
Note: if you detach the public IP address you will still be charged for it. For not being charged during the next billing period, you can delete it.
If you want to reserve IP, then click on “Reserve public IP” and you will receive 1 unique public IP.