In computer networks, to download is to receive data from a remote system, typically a server such as a web server, an server, an email server, or other similar systems. This contrasts with uploading, where data is sent to a remote server.
A download is a file offered for downloading or that has been downloaded, or the process of receiving such a file.
Downloading generally transfers entire files for local storage and later use, as contrasted with streaming, where the data is used nearly immediately, while the transmission is still in progress, and which may not be stored long-term. 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.
Downloading is not the same as data transfer; moving or copying data between two storage devices would be data transfer, but receiving data from the Internet is downloading.
Downloading media files involves the use of linking and framing Internet material, and relates to copyright law. Streaming and downloading can involve making copies of works that infringe on copyrights or other rights, and organizations running such websites may become vicariously liable for copyright infringement by causing others to do so.
Open hosting servers allows people to upload files to a central server, which incurs bandwidth and hard disk space costs due to files generates with each download. Anonymous and open hosting servers make it difficult to hold hosts accountable. Taking legal action against the technologies behind unauthorized "file sharing" has proven successful for centralized networks (such as Napster), and untenable for decentralized networks like (Gnutella, BitTorrent).
Downloading and streaming relates to the more general usage of the Internet to facilitate copyright infringement also known as "software piracy". As overt static hosting to unauthorized copies of works (i.e. centralized networks) is often quickly and uncontroversially rebuffed, legal issues have in recent years tended to deal with the usage of dynamic web technologies (decentralized networks, trackerless BitTorrents) to circumvent the ability of copyright owners to directly engage particular distributors and consumers.