Streaming Versus Download

It’s important to understand the difference between streaming content and downloading it. When you download a file, you click a link on a Web page that corresponds to a file on a Web server somewhere, watch the little papers fly across the screen, and wait for a confirmation that the download is complete. When the download is complete, a copy of the original file has been safely stored somewhere on your computer’s hard disk. The original file remains on the Web server, where it is available for others to copy. This act of copying is similar to copying a file locally from a floppy disk to your hard disk drive.

When you download a digital media file, such as a song or video, the process is the same. You click a hyperlink on a Web page that points to a file on a Web server. Your browser initiates the process of copying the file from the server. After the file has been copied to your hard disk, you can open and play it using a player application such as Windows Media Player.

The main advantage of downloading is that the file you download can be of any type: music file, text file, bitmap, and so on. And you can play the file over and over because, once downloaded, it resides on your computer’s hard disk. A disadvantage is that downloading files takes time, and you have to wait for all of the data to be copied from the server to your hard disk before you can play or view the file. Why? Because the application you will use to view the file cannot access it until the download is complete.

But what if you could skip the download process and simply play the data in real time as it is being received by your computer? Instead of waiting for an entire video to be copied, for example, your player application could play it as soon as the first chunk of video arrives. This is the concept of streaming. Content is played as it is received from a server over a network, and it is not saved to your hard disk.

With streaming media, you get instant gratification—there is no download wait. Streaming a prerecorded audio or video file is like playing a CD or tape. You have all the same playback controls, like play, pause, stop, and rewind. The only thing you don’t have is the physical media, such as CD or tape. You can choose what you want to listen to and when you want to listen to it.

Streaming also enables you to do live broadcasting, just like a radio or television station, except the broadcast is over the Internet.

But streaming does have disadvantages. Real-time playback of audio and video is highly dependent on the bit rate of the content and the bandwidth available on the network that is being used to deliver the stream.