In computer networks, to download means to receive data to a local system from a remote system, or to initiate such a data transfer. Examples of a remote system from which a download might be performed include a web server, FTP server, email server, or other similar systems.
A download can mean either any file that is offered for downloading or that has been downloaded, or the process of receiving such a file.
The term downloading is distinguished from the related concept of streaming, which indicates the receiving of data that is used nearly immediately as it is received, while the transmission is still in progress and which may not be stored long-term, whereas in a process described using the term downloading, this would imply that the data is only usable when it has been received in its entirety.
Increasingly, websites that offer streaming media or media displayed in-browser, such as YouTube, and which place restrictions on the ability of users to save these materials to their computers after they have been received, say that downloading is not permitted. In this context, download implies specifically "receive and save" instead of simply "receive". However, it is also important to note that downloading is not the same as "transferring" (i.e., sending/receiving data between two storage devices would be a transferral of data, but receiving data from the Internet would be considered a download).