Everyone knows speed is important when it comes to the Internet. When there was only dial up, we were limited to 56k, or 56 Kbps (meaning 56 kilobits per second or 56,000 bits each second), and even that was a theoretical limit. With broadband, two separate speeds became important to understand, upstream and downstream, also referred to as upload and download speeds, respectively. To understand downstream speeds, you need to know what the numbers mean and how they affect your Internet use.
Downstream, also be called "download," is the movement of files or data to your computer from elsewhere, even if only for temporary use. It is the rate at which your Internet connection can move these files from remote websites and servers to your computer.
Downstream speeds can range from 56 kilobits per second (Kbps) for dial up to 50 megabits per second (Mbps) for the fastest fiber-optic network connections offered by some Internet service providers. The average DSL connection is from 1 to 10 Mbps. Cable modems average 10 to 20 Mbps. Satellite is slow compared to some of these other connections with download speeds from 750 Kbps to 2 Mbps.
Even if you are only viewing one web page, the files for that page are temporarily downloaded to your computer. Downstream speed can be vital if you are downloading music files, videos or other large files and want them to run smoothly without pausing or need to download quickly without a long wait.
Kilobits and megabits are the units of measurement for downstream speeds, but for many people, that doesn't help them understand how fast their download speeds really are. Every file on a computer is made up of bits. Eight bits is the equivalent of 1 byte. If you want to download a 1 megabyte file, it can be downloaded in 1 second with an 8 Mbps connection. To better imagine how much downstream speed you need, an average email is between 50 to 100 Kbps, a photo taken on a digital camera can be from 5 to 10 megabytes and a full-length movie can be from about 700 megabytes to several gigabytes, depending on the length and type of compression used.