Video content is ubiquitous on the Internet. The vast majority of sites deliver video content by streaming it. Streaming video is delivered to the end user in small packets that play even as later portions of the video continue to download. Some interpretations limit the term "streaming" to live content, but video-on-demand (VOD) mostly follows the same delivery process and typically is considered "streaming video." This delivery process presents advantages and disadvantages.
Advantage -- Minimal Wait
Video files are large, so downloading the entire file takes considerable time. Streaming video allows the end-user to start viewing the video quickly, sometimes within a few seconds. This benefits both the end-user and the host site. The end-user can decide whether she wishes to view the entire video, without having to endure a long download before she can decide. For the host site, the quick start tends to keep end-users on the site and interacting, increasing the chances that the user will click on a related link or an advertisement.
Advantage -- Professional Training
Streaming video enables people to conduct real-time training sessions, such as webinars, with clients or coworkers. Equally important, the trainer can provide this training from any location. If a company's expert is out of town, he can still present the relevant material or process without the inconvenience of a cross-country or international flight.
Advantage -- Education
Educational institutions use streaming video to augment educational opportunities, particularly online education. Instructors can deliver live lectures and provide VOD versions of the same lectures for students to review. This helps to engage students at both the auditory and visual level, which improves retention of material.
Disadvantage -- Bandwidth
Bandwidth availability is a key problem in the delivery of streaming video. If the sender overestimates or underestimates the available bandwidth, the video quality will suffer. Errors in bandwidth estimation lead to loss of packet or delays in packet delivery, which can cause degraded video quality or jerky video playback. While various error control methods, such as buffering, can limit these problems, no solution completely eliminates them.
Disadvantage -- Cost
Costs mount quickly with live streaming video. Expensive camera equipment and high-end computer equipment are needed to transmit the feed. In addition, securing enough bandwidth to support a live broadcast typically requires the services of an Internet service provider (ISP). While potentially less expensive than managing the entire process in-house, the costs for bandwidth usage can still run high.