These are the tokens that are based on existing blockchain platforms, such as Ethereum, Omni, NEO, and so on. A token helps in creating a coin faster, and supports a quick go-to market strategy so that most of the time can be invested in further development of a self-hosted blockchain. 

There are examples of various blockchain projects, which start as a token and post a successful ICO once they start their own fully supported blockchain complete with a coin. Since it is faster and easier to develop a token as compared to a coin, it becomes easy for such projects to gain traction and also get launched in no time, and most of the time can be invested in other important tasks such as whitepaper creation, ICO, and so on.