Uploading and downloading

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 webserver, 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.

It has become more common to mistake and confuse the meaning of downloading and installing or simply combine them incorrectly together.

The inverse operation, uploading, can refer to the sending of data from a local system to a remote system such as a server or another client with the intent that the remote system should store a copy of the data being transferred, or the initiation of such a process. The words first came into popular usage among computer users with the increased popularity of Bulletin Board Systems (BBSs), facilitated by the widespread distribution and implementation of dial-up access the in the 1970s
DownloadThe use of the terms uploading and downloading often imply that the data sent or received is to be stored permanently, or at least stored more than temporarily. In contrast, the term downloading is distinguished from the related concept of streaming, which indicates the receiving of data that is used near 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.[1] 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 of data).

Sideload
When applied to local transfers (sending data from one local system to another local system), it is often difficult to decide if it is an upload or download, as both source and destination are in the local control of the user. Technically if the user uses the receiving device to initiate the transfer then it would be a download and if they used the sending device to initiate it would be an upload. However, as most non-technical users tend to use the term download to refer to any data transfer, the term "sideload" is sometimes being used to cover all local to local transfers to end this confusion.

Remote Upload
When there is a transfer of data from a remote system to another remote system, the process is called "remote uploading". This is used by some online file hosting services.

Remote uploading is also used in situations where the computers that need to share data are located on a distant high speed local area network, and the remote control is being performed using a comparatively slow dialup modem connection.

For example:

    * The user remotely accesses a file hosting service at MyRemoteHost.
    * The user finds a public file at PublicRemoteHost and wants to keep a copy in their MyRemoteHost.
    * To have it done they "remote upload" the file from PublicRemoteHost to MyRemoteHost.
    * None of the hosts are located on the user's local network.

Without remote uploading functionality, the user would be required to download the file first to their local host and then re-upload it to the remote file hosting server.

Where the connection to the remote computers is via a dialup connection, the transfer time required to download locally and then re-upload could increase from seconds, to hours or days.
(http://en.wikipedia.org)