Streaming media is multimedia that is constantly received by and presented to an end-user while being delivered by a provider. The verb “to stream” refers to the process of delivering media in this manner; the term refers to the delivery method of the medium rather than the medium itself.
A client media player can begin playing the data (such as a movie) before the entire file has been transmitted. Distinguishing delivery method from the media distributed applies specifically to telecommunications networks, as most of the delivery systems are either inherently streaming (e.g., radio, television) or inherently nonstreaming (e.g., books, video cassettes, audio CDs). For example, in the 1930s, elevator music was among the earliest popularly available streaming media; nowadays Internet television is a common form of streamed media. The term “streaming media” can apply to media other than video and audio such as live closed captioning, ticker tape, and real-time text, which are all considered “streaming text”. The term “streaming” was first used in the early 1990s as a better description for video on demand on IP networks; at the time such video was usually referred to as “store and forward video”, which was misleading nomenclature.
Live streaming, which refers to content delivered live over the Internet, requires a form of source media (e.g. a video camera, an audio interface, screen capture software), an encoder to digitize the content, a media publisher, and a content delivery network to distribute and deliver the content.
In the early 1920s, George O. Squier was granted patents for a system for the transmission and distribution of signals over electrical lines which was the technical basis for what later became Muzak, a technology streaming continuous music to commercial customers without the use of radio.
Attempts to display media on computers date back to the earliest days of computing in the mid-20th century. However, little progress was made for several decades, primarily due to the high cost and limited capabilities of computer hardware. From the late 1980s through the 1990s, consumer-grade personal computers became powerful enough to display various media. The primary technical issues related to streaming were:
having enough CPU power and bus bandwidth to support the required data rates
creating low-latency interrupt paths in the operating system to prevent buffer underrun.
However, computer networks were still limited, and media were usually delivered over non-streaming channels, such as by downloading a digital file from a remote server and then saving it to a local drive on the end user’s computer or storing it as a digital file and playing it back from CD-ROMs.