The blockchain initially started as the technology underpinning bitcoin. However, its early success to prove itself as a trust machine and intermediary killer put pressure on a variety of industries to both adapt to and adopt this new technology.

Consequently, many variations of Satoshi's original blockchain have been developed. In this final section, we will take a look at the major types of blockchain technologies.

Currently, blockchain solutions can be classified into four basic models with different paradigms. The distinction between them is driven by two main criteria: the network type and the implemented access control model; in other words, who is allowed to join the peer-to-peer network (run a node) and access the blockchain records.

The following table gives an overview of the different types, with a basic description of each model:

You might be wondering—which one of these types of blockchain might be appropriate for your project?

The answers depend on your project's requirements. Generally, in a trustless environment (for remittance systems, proving provenance, and so on), we tend to use a public blockchain, while the other models are fit for actors who share a pre-existing trust and desire to build shared services.

Private blockchains are suitable for building faster local testing environments, or to avoid the cost of transacting, whereas the BaaS model is a suitable solution for easy deployment and high scalability.