Cryptocurrency Basics: Terms, Types, and Concepts

What this hub covers

Cryptocurrency is money that moves on shared ledgers. No bank sits between the sender and the receiver. A transaction is signed with a private key. The network checks the signature. The payment lands in a ledger that thousands of independent computers hold and verify. The bitcoin.org walkthrough traces this path step by step, and this library follows it ^[1].

This hub is the front door to the basics. It holds the pages that define what cryptocurrency is, how a blockchain settles, and what decentralized finance does. It also holds the stablecoin types series and the glossary that defines every term the rest of the site uses.

The one idea everything hangs on

A blockchain is a ledger anyone can hold in full and verify from scratch. New payments are grouped into blocks. Each block locks in the one before it with cryptography. Changing an old block means redoing the work that secured every block after it ^[1]. That property, verifiable history without a trusted operator, is the reason every product in this space exists. Every page in this library traces back to it.

Ownership in that system is a key pair. The private key signs. The network checks the signature against the public address. Lose the key and the funds are unreachable. There is no operator to call. The wallet pages in the basics family treat that fact with the weight it deserves. It is the one place in this system where an error cannot be undone.

The stablecoin types series

Stablecoins are the largest working use of this technology. The basics family covers their types one by one. It opens with what a stablecoin is. Then it walks the classes: the fiat-backed form, the crypto-backed form, the algorithmic form, taught as the historical class it became. And the gold-backed form, which carries the commodity class folded in. Each page states what backs the type. Each states what its failure mode looks like. Each points at the historical record where it exists.

The series closes with the question every reader eventually asks. What are the risks, and what should you weigh? That page runs six checks with dated values and no verdicts. The stablecoins hub carries the token pages that put figures behind those definitions.

The glossary

Every term this site uses gets a glossary page, ten at launch. Each entry defines its term in plain language, from a dated source. Volatile terms date every number they use ^[2]. Each entry links the pages where the term does real work. A definition is never a dead end.

• Custody, who holds the keys, self or third party, with the hot and cold axis under it.

• Oracle, the applications that carry off-chain data to smart contracts.

• Real-world assets, off-chain claims recorded on-chain as tokens.

• Gas, the unit that meters computational effort and prices it.

• Total value locked, the DeFi deposit aggregate, quoted with its provider and date.

• Depeg, a sustained departure from the value a stablecoin promises to hold.

• On-ramp and off-ramp, the services that cross between fiat and crypto.

• Layer 2, networks that post their data back to Ethereum.

• Stablecoin basket, one term with two senses, defined apart.

• Reserve ratio, issuer reserves against circulating tokens, both dates shown.

The finance pages

Decentralized finance is the part of this system where the ledger lends, trades, and pays. No firm stands in the middle. The finance pages cover it as mechanics. A lending contract holds collateral and issues a loan against it. A swap pool prices a trade against the assets it holds. A yield figure is a rate someone pays for borrowing, not interest a bank pays you. The pages keep those distinctions sharp. Most DeFi confusion starts when a lending rate is read as a deposit rate.

The finance family also carries the lending section that moved in from its own page, rewritten against current sources. Risk is stated plainly there. Smart contract risk has no deposit insurance behind it, and a protocol failure can be total.

How to use this hub

Start where the question is. If the words are the problem, start with the what is cryptocurrency page or the glossary. If the mechanics are the problem, start with the blockchain page. If DeFi is the subject, the DeFi page and the finance page hold it. The hub links its own pages below as they land, and every one of them links back here.

Two practice pages complete the basics family. Cold versus hot wallets compares the two custody models on sourced criteria, with no winner named. And seed phrase safety states the backup hygiene both models depend on, rule by rule, source by source. Both carry the heaviest weight this site gives a page. An error in custody cannot be undone.

Underneath both sits one definition. What is a crypto wallet explains the tool itself: keys, addresses, signing, and the recovery phrase, from protocol documentation. Two subject pages join the family from the same research pass. How to avoid crypto scams collects the red flags five regulators publish, with dated loss figures from the FBI’s 2025 report and the ICO era as history. What are privacy coins explains Monero and Zcash mechanics, why mixers are a different thing, and where the coins are restricted, each claim carrying its evidence tier.

Where this hub sits

Bitcoin, the first and largest network, has its own hub. The networks assets move on sit under chains. Spending is the spend hub’s subject. The rules that govern all of it start at regulation. Each hub links the others, so the trail never dead-ends.