The process to validate new blocks in the Flow Blockchain happens through nodes.

Nodes are similar to Validators or Miners in other blockchains, as they're the block creators, but:

Unlike most blockchains, not all Flow nodes are equal. Flow nodes all specialize and fulfill a specific role in the operation of the network. Collection, consensus, execution, verification and access nodes are all staked nodes while the observer node is not staked.

Collection: Collection nodes are bandwidth-optimized nodes divided by the protocol into several cooperating Clusters. Their first task is managing the transaction pool and collecting well-formed transactions to propose to Consensus nodes.

Consensus: Consensus nodes form and propose blocks in a manner similar to traditionally-structured proof-of-stake blockchains ... Consensus nodes assemble the transactions into blocks and finalize them through voting.

Execution: Execution nodes are the most resource-intensive nodes on the Flow network, responsible for executing transactions and maintaining the Execution State — a cryptographically-verifiable data store for all user accounts and smart contract states — as well as responding to queries related to it.

Verification: Verification nodes are responsible for confirming the correctness of the work done by Execution nodes. Individual Verification nodes only check a small amount of the total computation, but collectively they check every computation many times in parallel.

Access: Access nodes act as a proxy to the Flow network. The Access node routes transactions to the correct collection node and routes state queries to execution nodes.

Observer: An observer node provides locally accessible, continuously updated, verified copy of the block data. It serves the Access API but unlike an access node, an observer node does not need to be staked, and anyone can run it without being added to the approved list of nodes.

Archive: The Archive node provides a scalable and efficient way to access the history of Flow protocol and the execution state for the current spork.This node can be run by anyone without being staked or added to the approved list of nodes.

There are seven types of Nodes in Flow Blockchain, and all the staked Nodes required a specific stake amount.

Collection Node > 250,000 $FLOW
Consensus Node > 500,000 $FLOW
Execution Node > 1,250,000 $FLOW
Verification Node > 135,000 $FLOW
Access Node > 100 $FLOW
Observer & Archive nodes doesn't require Staked $FLOW

Flow Decentralization Progress