For most people, the blockchain technology refers to cryptocurrencies, and more specifically to Bitcoin. But the reality is that the blockchain technology could be used for a great variety of projects.
It is well possible that the blockchain itself refers to any data or service, without necessarily referring to a currency.
But blockchain and cryptocoins go hand in hand, as cryptocurrencies offer a convenient way to reward users of the blockchain network and ICOs (Initial Coin Offering) prove to be a suitable way for raising funds for new projects.
In this respect, tokens are issued to finance projects and to pay users of a blockchain to encourage them to help the chain moving forward. It is like issuing shares in the stock market, but here, users and investors overlap in the sense that users would also be rewarded with shares and become shareholders automatically. The system holds solid as long as the community of users trust each other, hence tokens have value as long as the confidence reigns.
The problem is that the ICOs are not well regulated yet; therefore, risks are elevated.