IP range

[jotto84]

how do you know if an ip address is local or an internet address?

[moonlight burner]

Local addresses are usually non-routable ones, according to RFC 1918, they are :

10.0.0.0-10.255.255.255

172.16.0.0-172.31.255.255

192.168.0.0-192.168.255.255

[jotto84]

what does non-routable mean?

[Great_One]

they are private ip address ranges meant to be used on internal networks.
They are not meant to be used on the internet, routers are not supposed to broadcast these ip's to the internet.