What is it?
"Simply defined, crowdsourcing represents the act of a company or institution taking a function once performed by employees and outsourcing it to an undefined (and generally large) network of people in the form of an open call. This can take the form of peer-production (when the job is performed collaboratively), but is also often undertaken by sole individuals. The crucial prerequisite is the use of the open call format and the large network of potential laborers." -Jeff Howe coining the term 'crowdsourcing' in "Wired" magazine in 2005.
How is it commonly used?
Crowdsourcing is used in many ways, but there are four main approaches: Crowd Wisdom, Crowd Creation, Crowd Voting, and Crowd Funding. Crowd wisdom is when the "knowledge of the crowd" is harnessed to solve problems. One common example of this is the popular "yahoo answers". Crowd Creation involves individuals- no qualifications neccesary- to create, translate or define something. Some common examples include: iStockPhoto, Linux, and NASA's clickworkers. Crowd voting uses a community to filter and rank different types of content. Perhaps one of the biggest examples of crowd voting would be the popular TV show "American Idol". Crowd funding is when groups that are typically under-funded or struggling are offered funds through corporate establishment. Two common examples of these groups are aspiring entrepeneurs or musicians. a good example of this is a website called Kiva.