Uploading and downloading are two terms used in computing to refer to data transfer. In brief, files are considered uploaded when they are transferred from a computer to a central server. Files are downloaded when they are transferred from a server to a smaller peripheral unit. When data is being transferred from one system to another, it is either being uploaded or downloaded, depending on the circumstance.

Uploading usually refers to copying files from a smaller peripheral system to a larger central system. For example, a user might upload files from his or her cellphone to a personal computer. These files in turn might be uploaded again to a central server. The uploading of small files might take only a few seconds, while larger graphic-heavy files could take hours. In most cases, uploading can be accomplished while the computer is performing other tasks, although it may slow the computer down if it is handling large files.

Downloading refers to the transfer of data from a central system to a smaller system. For example, the same files uploaded to the server above might be downloaded for viewing by another user. When downloading files, the larger the file, the more time it takes to complete the transfer, just as is in uploading. Downloaded files usually remain on the server unless the user specifies otherwise, meaning that others can access the information.

Uploading and downloading are used on a daily basis by Internet consumers. Email is downloaded from a server while replies are uploaded to be sent out. The source code of a web page is downloaded to the end user’s computer so that he or she can view the content. Other consumers download games, audio files, or video for personal amusement. Consumers who host their own websites may use a specialized File Transfer Protocol (FTP) program to upload files to their servers, or download files from other locations.

Essentially any information that can be digitized can be uploaded or downloaded. The terms refer to moving information around an informational web, whether it be a home or office network or the entire Internet. A number of programs have arisen to assist consumers with uploading and downloading, also called file sharing. Uploading and downloading have greatly simplified the free exchange of information which has characterized the computer age.