They are all terms that indicate a person who is supporting a certain project or cause through donations of labor or money. If you wanted to start a lemonade stand, and I gave you the money for the lemons or just gave you lemons, you could say that I'm backing your lemonade stand. Each term can have a slightly different meaning... Backers is usually used with the crowd-funding sites, like Kickstarter or GoFundMe. A person pledges money (they agree to pay a certain amount if enough people also agree to fund the project) and they often receive a reward for funding the project. Funders if very similar, if less used, to backers. Sponsors are a little different. A sponsor gives a person money, and in return, that person will advertise for (or give a "shout out" to) the sponsor. For example, a company can sponsor a sports team. You'll see that company's logo appear on the walls of the stadium, and its advertisements will be played during the airing of the game. A business venture is essentially an attempt to monetize a particular service or product. "Venture" is similar to the longer form "adventure" (though more serious in connotation). Business simply describes the type of venture. You might ask me to help you with your business venture, and then explain that you're starting a lemonade stand and need lemons. Business ventures can be started by a large company going into a new line of business, such as Microsoft choosing to create its search engine Bing, but the qualifying aspect is that there is always something new. A new line of business, a new company entirely, etc.