Almost anyone who has a bit of money can invest via seed funding from family and friends to founders and more. Many companies tend to prefer to have investors who are known and are close to them, however, outside investors, such as venture capital and angel investment can also be seed funders.
Angel investors are those who tend to invest in start-ups and are classed as a riskier venture as there is no previous track record of the business so far. In exchange for their investment, they tend to expect an equity stake in the company. Venture capital financing is a private equity capital that can be provided at various stages or funding rounds.
Many start-up businesses tend to get their seed funding through other projects too such as via crowd funding systems and Kickstarter among others.