What type of blockchain can anyone participate in without the need for permission?

A public blockchain is a type of blockchain that allows anyone to participate without any restrictions or permissions. This means that anyone can join the network, validate transactions, and even contribute to the consensus process. Public blockchains are characterized by their open nature, where anyone can view the transactions and data stored on the blockchain. This transparency helps to enhance trust among users, as all transactions can be independently verified by anyone.

In contrast, a private blockchain restricts participation to a select group of users or entities, meaning that only authorized participants can access, validate, and interact with the blockchain. Permissioned blockchains share a similar concept, where access is controlled, and specific permissions are required to join or perform certain actions.

Hybrid blockchains combine elements of both public and private blockchains, allowing for some degree of access control while also benefiting from the transparency of public blockchains. However, only public blockchains enable unrestricted participation from anyone in the network, making it the right choice for this question.