Definition - What does Downstream mean?
In IT, "downstream" refers to the transmission of data to an end user or toward an end user from a central server or point of origin. This is in contrast to upstream transmissions, which move from the end user to the central repository. The terms "uploads" and "downloads" are often used to refer to upstream and downstream transmissions respectively.
Another similar set of terms is "uplink" and "downlink," which are often applied to satellite systems.
Techopedia explains Downstream
When considering downstream transmissions, experts have to recognize specific transmission protocols, such as TCP/IP, FTP and HTTPS. They may rate performance according to MBpS or another metric. Downstream transmissions often have a faster rate than corresponding upstream transmissions, and are generally easier to broadcast. In calculating downstream speed from one point to another, engineers and analysts may have to factor in multiple transmission segments, as well as problems such as bottlenecks.