Real Network's Real Video
Real Videos are played back using the so-called 'Real Player'. This software is available as a free browser plug-in or as a separate program. When a request for a Real Video is executed, the data is first buffered and then the first video images are displayed on the PC. Remaining parts of the video are loaded automatically in the background. A Real Video file is never offered as a complete file for download, a duplicate of the video clip is therefore never stored on the user's hard disk by default. The video quality is strongly dependent on the existing Internet connection. Not only does the type of connection (modem, ADSL or LAN) play a role, the temporary bandwidth is also important. For example, if too many users have logged in to the video server, the bandwidth is reduced at the price of the quality. Another aspect is the general Internet traffic load: if the network is overloaded, then even the best connection doesn't help. Some companies offer adapted bandwidths where the user confirms which device he is using to connect to the Internet (e.g. 33.6 for a modem or T1 for LAN). As long as you haven't logged into the Internet at rush hour, you can expect reasonable image and sound quality up to 10 frames per second when using a 56 kbps modem connection. If you have a cable modem or an ADSL connection it is even possible to watch a video in full-screen mode, but only when the server at the other end offers that. 28.8 modems however will only supply unsatisfactory results. All the disadvantages described above hardly apply within an intranet as these normally have enough resources in reserve.
Microsoft's Active Movie
Active Movie by Microsoft is hardly different to Real Video except for the format. Many providers (e.g. CNN ) offer their videos in both formats. The required format can then be selected according to the installed software (Real Video Player or Microsoft Media Player).