The Internet is a network of networks. You cannot connect to the Internet unless you are part of a network. Some networks of the Internet are owned by Internet Service Providers (ISPs). To connect you home computer to the Internet you first connect it to an ISP network and the ISP network then connects you to all other networks of the Internet. The ISP network assigns you an IP address. This address is referred to as a dynamic IP address since you are not necessarily assigned the same address every time you get connected. You operating system’s TCP/IP software exchanges data with the ISP network using the standards defined by a protocol called the Point-to-Point Protocol (PPP).

You can get connected to the Internet using different approaches. All approaches utilize modems (MOdulator-DEModulators). The modem on the sender side modulates the data into a form that is compatible with the employed transmission approach. The modem on the receiver side demodulates the data back into their original form. For instance, for regular dial-up Internet connections, the modem modulates the digital signal sent by the computer into an analog form that is to be transmitted on regular phone lines and at the receiver side the modem demodulates the signal back into its digital form. Some Internet connection approaches give data reception speeds (downstream or downloading speeds) that are higher than data sending speeds (upstream or uploading speeds) since usually the data that Internet users download are much more than the data they upload.