An Internet Protocol (IP) address is a numeric address that identifies a computer or network device on the internet, usually written in decimal notation, separated by periods. All resources on the Internet must have an IP address.
The format of an IP Address is four octets of 8 bits, which translates to (0-255).(0-255).(0-255).(0-255) in base 10.
Here at MIT, the first part of the IP Address will mostly be 18...if the Address is correct. In case it shows to be 10, then the device may be on the Voice VLAN, is connected to a private network, or there is some sort of interruption in the connection. If it is 169, this is a self-assigned IP and then there is a break in the connection.
IP Addresses can be either static or dynamic. Static IP Addresses have the advantage of being fixed for each machine, so it is easy to identify the machine in the future. It has the disadvantage of having disturbance when the location of the device is changed.
Dynamic IP Addresses are changing as can be interpreted by their name and so are not fixed, having the advantage of being available when a device is changing locations. Also for a particular server, less IP addresses are in use at a particular time, as no one has a fixed address and each time a new one is allocated.