ICO operates in a similar way to an IPO: investors invest in funds and receive a "stake" in the company. The main difference is that under ICO, the investor does not receive the real shares, but becomes the owner of cryptographic tokens, which are traded on crypto-exchanges for various crypto currency. Strictly speaking, tokens are not tied to shares or to any other form of ownership. In this case, ICO has much in common with crowdfunding: in both cases, as a rule, funds are collected for the implementation of a certain concept - that is, at a stage when the company still does not have any product.