Static and Dynamic IP address
When you connect to the Internet, your machine/network is assigned an IP address. This IP address is used by other computers to send and receive messages from your machine.
If your IP address never changes, it is known as a Static IP address. On the other hand, if your IP address changes after some time it is known as a Dynamic IP address.
Static IP addresses often belong to companies that host their own servers while dynamic IP addresses are typically allocated to home users who seldom host any servers.