Every device on a network has a unique identifying number called an IP address (Internet Protocol Address). IP addresses are formed in four parts called octets. Typically a IP address looks like this:
192.168.1.137
This address follows the IPv4 standards. Each of the 4 octets is separated by dots and can have a value from 0-255. IP addresses can either be dynamically assigned or statically assigned to a device, like your computer. With so many devices needing connectivity to computer networks and the internet, a new standard has been created to cope with the demand called IPv6.