According to Wikipedia, crowdfunding is the practice of funding a project or venture by raising monetary contributions from a large number of people. There has been some notable successes using crowdfunding. A good example is Pebble Watch which raised more than $10 million through crowdfunding some years ago.
Besides raising funds for equity or debt, crowdfunding can also be used for pre-selling products or services. Referred to in Wikipedia as reward crowdfunding, it can also be for motion picture promotion, free software development, inventions development and scientific research. However, for the purpose of this section, crowdfunding refers to raising funds for equity or debt in your startup.
There are some notable crowdfunding websites such as Kickstarter, Indiegogo and GoFundMe.