Almost everyone has heard of cryptocurrencies, yet few can clearly say what they actually are and how they work. Let us explain it from the basics, simply and without needless jargon, so that even a complete beginner understands.

What a cryptocurrency is

A cryptocurrency is digital money that exists only electronically and is issued by no state or bank. It has no form of coins or banknotes. Instead of a central authority (like a national bank), a network of computers all over the world takes care of its operation and records.

The best known is bitcoin, but there are thousands of cryptocurrencies. The word “crypto” refers to cryptography, that is the encryption that secures the whole system.

Blockchain: a ledger the whole network trusts

The heart of cryptocurrencies is the blockchain (a chain of blocks). Picture it as a public ledger in which all transactions are recorded and of which many computers around the world hold a copy at the same time.

  • Records are written into blocks, which are chained one after another.
  • Once a block is written, it cannot be changed unnoticed (that would conflict with the thousands of other copies).
  • Nobody keeps the ledger “under their thumb”, the whole network reaches agreement on its content.

That is precisely what makes the blockchain trustworthy without a bank having to guard it.

Decentralization: no bank and no boss

An ordinary bank account is controlled by the bank. With cryptocurrencies it is different: the network is decentralized, meaning there is no single central administrator. A large number of independent computers (nodes) agree on the correctness of the records. The advantage is resilience and independence, the disadvantage is that there is no customer support and nobody to reverse a mistake.

A wallet, an address and a private key

To use a cryptocurrency you use a wallet. It has two important parts:

  • The address (public key) is like an account number. You can freely share it when you want to receive a payment.
  • The private key is a secret password that proves the money is yours and lets you send it.

One golden rule applies: whoever has the private key owns the coins. If you lose it, you lose your funds irreversibly. If someone obtains it, they can rob you. There is an article on safely storing passwords, a password manager and two-factor authentication.

How cryptocurrencies are created: mining versus staking

New transactions need to be verified and recorded. There are two main ways the network agrees on who does it:

  • Proof of Work, so called mining. Computers compete in solving demanding mathematical puzzles, and the winner writes the block and gets a reward. This is how bitcoin works. It is secure, but it consumes a lot of electricity.
  • Proof of Stake, so called staking. Instead of computing power, participants put their own coins into the network as a guarantee, and the network selects who writes the block. This is how today’s Ethereum works. It is far more economical.

Bitcoin, Ethereum and thousands of others

  • Bitcoin (BTC) is the first and best known cryptocurrency (from 2009, under the name Satoshi Nakamoto). It has a limited supply, a maximum of 21 million coins, which is why it is called “digital gold”.
  • Ethereum (ETH) is a programmable network. It enables smart contracts (self-executing agreements) and apps, not just sending money.
  • Altcoins are all the other cryptocurrencies besides bitcoin.
  • Stablecoins (for example USDT, USDC) are pegged to an ordinary currency, usually the dollar, so their price is stable.
  • Tokens and memecoins are often speculative and very risky.

Where they are bought and where they are stored

Cryptocurrencies are bought and sold mainly on exchanges, such as Coinbase, Binance or Kraken. When registering, you usually have to verify your identity (KYC).

For storage we distinguish:

  • A hot wallet is online, in an app or on an exchange. Convenient, but more exposed to attacks.
  • A cold wallet is a hardware device offline. Safer for long-term holding.

For larger amounts the rule “not your keys, not your coins” applies: funds on an exchange are technically not fully under your control. At least enable two-factor authentication.

Risks and scams

This is the most important part, because a lot of money is lost in cryptocurrencies:

  • High volatility. Prices rise and fall by tens of percent in a short time.
  • Irreversibility. Nobody returns a sent transaction or funds sent by mistake.
  • Losing the key = losing the money. There is no password reset.
  • Scams. Fake exchanges and wallets, phishing, fraudulent “investments” with guaranteed profit, pyramid schemes, pump and dump (artificially inflating the price) and rug pulls (the creators vanish with the money). This relates to the articles social engineering and AI scams and fraudulent messages.
  • No consumer protection. With a scam you have nobody to turn to like with a bank.

Golden rule: if someone promises you a guaranteed or quick profit, it is a scam.

Taxes and law

In Slovakia, selling cryptocurrency at a profit is taxable income. The rules are evolving, so check your tax obligations with an expert or the tax authority. Keep records of your purchases and sales.

Practical tips for a beginner

  • Invest only as much as you can afford to lose. Crypto is highly risky.
  • Use proven exchanges and do not download apps from unknown sources.
  • Protect your private key and for larger amounts consider a hardware wallet.
  • Enable two-factor authentication and a strong password, more in the article safe online shopping.
  • Do not start with memecoins or “tips” from the internet. Understand the basics first.

Conclusion

A cryptocurrency is digital money without a bank, built on the blockchain, that is a public ledger guarded by the whole network. Ownership is determined by the private key, new coins are created by mining or staking, and they are bought on exchanges. It is an interesting technology, but also a risky world riddled with scams. If you venture into it, go slowly, educate yourself and risk only what you can bear to lose.

Need advice on securing devices and accounts, or protecting yourself from scams? Get in touch, we will be happy to help.

This article is part of our Software and system overview.