As we mentioned in the previous chapters, we can put blockchains into two broad categories, depending on who owns them and how accessible are they.
First, we have public blockchains, which are open source projects, with free access for anyone to join the network and use it, support it, contribute to it, or build businesses on it.
Then, we have private blockchains, which are not open source, and have restricted access to only users and entities who have been approved by the organization that owns and manages the network.
In each of these categories, there are projects with general purpose blockchains such as Ethereum; however, there are also some application-specific blockchains present. General purpose technology is used to provide foundational infrastructure and building blocks to create applications on top of. For example, you can refer...