A cryptocurrency is a crypto asset that works as a medium of exchange wherein individual coin ownership records are stored in a blockchain using strong cryptography to secure transaction records, to control the creation of additional coins, and to verify the transfer of coin ownership. It does not exist in physical form, is not issued by a central authority and uses decentralised control as opposed to traditional central banking systems. Each cryptocurrency works through a blockchain, that serves as a public financial transaction database.
In cryptocurrency networks, mining is a validation of transactions. The miners obtain new cryptocurrency as a reward and this reward decreases transaction fees by creating a complementary incentive to contribute to the processing power of the network.
A cryptocurrency wallet stores the public and private “keys” or “addresses” which can be used to receive or spend the cryptocurrency. With the private key, it is possible to write in the public ledger, effectively spending the associated cryptocurrency. With the public key, it is possible for others to send currency to the wallet.
Most cryptocurrency tokens are fungible and interchangeable but unique non-fungible tokens also exist for certain purposes. Non-fungible tokens have started gaining wider recognition and acceptance in the year 2021, especially for crypto assets.
The legal status of cryptocurrencies varies from country to country. Some have allowed it as legal while others have banned it as illegal. Some countries like India are in the process of formulating new law to regulate/prohibit dealing in cryptocurrencies. See crypto laws page and its related resource for more info on global cryptocurrency laws.