Simplified Payment Verification (SPV) is a method of verifying transactions on a blockchain without downloading the entire chain of blocks. Block headers are enough, which makes the technology the foundation of lightweight crypto wallets.

Fintech is an industry that brings together companies that use technology and innovation to transform financial services. It includes payment services, neobanks, and also blockchain-based solutions.

A fork in a blockchain is a change to the rules by which a block is recognized as valid. There are soft forks and hard forks, which affect the unity of the network in different ways.

Freicoin is a cryptocurrency built around the economic idea of money with a storage fee. It is based on the concept of "free money" by economist Silvio Gesell.

Difficulty is a network parameter that governs how hard it is to find a new block. It automatically adjusts to the network's total power, keeping the block issuance time stable.