Why is it necessary to separate two in counting the number of devices on a subnet?

Question

WiFi

I studied what subnets are and nowhere could I understand exactly why it is still necessary to separate two when counting free ip and when counting the ip mask / borders that a subnet can give out - there is 1 more ip than the number of free ???

Answer 1

Because there are only 256 ip addresses in the /24 mask. Of these, 2 "service". In your example, 192.168.1.0 is the network address and 192.168.1.255 is the broadcast address, leaving 254 addresses available to hosts.

Answer 2

Because the two addresses to be separated are official and cannot be occupied. They seem to be there, but they are not.