Streaming is the continuous transmission of data over a network. Data streams are a continuous flow of data records, the end of which can usually not be foreseen in advance. The data records are processed continuously as soon as a new data record is received. The amount of data records per unit of time (data rate) can vary and possibly become so large that the limited resources are insufficient for further processing and the recipient has to react accordingly (e.g. discarding data records). In contrast to other data sources, data streams can only be processed continuously record by record - in particular, in contrast to data structures with random access (such as arrays), only sequential access to the individual data records is usually possible.

Data streams are often used for interprocess communication (communication between processes on a computer) and for the transmission of data over networks, especially IoT and for streaming media. They can be used in many ways within the framework of the Pipes and Filters programming paradigm. Pipe is a common functionnality of Unix shells. Examples of data streams are weather data, system metrics, factory devices information, as well as audio and video streams (streaming media).