Photo sharing is the publishing or transfer of a user's digital photos online, thus enabling the user to share them with others (publicly or privately). This function is provided through both websites and applications that facilitate the upload and display of images. The term can also be loosely applied to the use of online photo galleries that are set up and managed by individual users, including photoblogs. Sharing means that other users can view but not necessarily download the photos, users being able to select different copyright options for their photos.
The first photo sharing sites originated during the mid to late 1990s primarily from services providing online ordering of prints (photo finishing), but many more came into being during the early 2000s with the goal of providing permanent and centralized access to a user's photos, and in some cases video clips too. Webshots, SmugMug, Yahoo! Photos and Flickr were among the first. This has resulted in different approaches to revenue generation and functionality among providers.
While photoblogs tend only to display a chronological view of user-selected medium-sized photos, most photo sharing sites provide multiple views (such as thumbnails and slideshows), the ability to classify photos into albums, as well as add annotations (such as captions or tags) and comments. Some photo sharing sites, even small ones with only a few million photos, provide complete online organization tools equivalent to desktop photo management applications.