In Short - Cryptocurrency is typically decentralized digitized money designed to be used over the internet.

Central to the appeal and functionality of Bitcoin and other cryptocurrencies is blockchain technology. As its name indicates, blockchain is essentially a set of connected blocks or an online ledger. Each block contains a set of transactions that have been independently verified by each member of the network.

Besides paying for Crypto you have some "FREE" options like Faucets - Cloud Mining - Air Drops - Mobile/Browser Mining. Most Mining Sites offer you a reward paid in crypto - when you complete a task. This is your best option if you do not have funds to invest.