What is crypto currency and how it works?

"Crypto" refers to the various encryption algorithms and cryptographic techniques that safeguard these entries, such as elliptical curve encryption, public-private key pairs, and hashing functions.
A cryptocurrency is a form of digital asset based on a network that is distributed across a large number of computers. Cryptocurrency transactions are recorded on a shared, digital ledger called a blockchain. This is a decentralized technology, spread across many computers, that records every transaction.
Are cryptocurrency and Blockchain the same?

No. Blockchain is the technology that allows for cryptocurrencies to work. It is a decentralized and digital ledger of transactions used for cryptocurrencies and other assets/functions

Here are the terms used in cryptocurrency technology.
Crypto — an umbrella term for all digital and/or virtual currencies
Coins — Generally, any cryptocurrency that has its own separate blockchain
Tokens — Generally, any cryptocurrency that is built on top of an existing blockchain, e.g., some companies issue their own cryptocurrencies, called tokens, which can be used to purchase goods or services specifically from issuing company
ICO — Short for Initial Coin Offering, this is analogous to a privately held company going public via an initial public offering (IPO)—a way to raise funds for a new cryptocurrency or expand services for existing coins