Crypto (short for cryptocurrency)
Cryptocurrency is a new form of digital money powered by cryptography.
It all started in 2008 with Bitcoin. You could use it to send funds to anyone anywhere globally. What made crypto different from normal bank transfers or other financial services like Paypal or Alipay is that there was no middleman for the first time.
A middleman is a central authority like a bank or government that intervenes in a transaction between the sender and recipient. They have the power to surveill, censor or revert transactions and they can share the sensitive data they collect about you with third parties. They also often dictate which financial services you have access to.
Things are different with crypto. Transactions directly connect sender and recipient without having to deal with any central authority. Nobody else will have access to your funds and nobody can tell you what services you can use. This is possible because of the blockchain technology upon which cryptocurrencies operate.
Blockchains use cryptographic techniques to ensure that your funds are safe. Similar techniques have been used in the banking industries to ensure the security of monetary transactions for years. So you could say cryptocurrencies have a bank level of security.