Most people have heard about Bitcoin by now, but many don't know how Bitcoin works. The idea behind Bitcoin is the blockchain, which is basically a public ledger. While anyone can look at Bitcoin's blockchain, if you want to change it, you have to have private keys to a Bitcoin.
When a person makes a Bitcoin transaction, they use a private key to transfer the Bitcoin (really just a private key) to another address. The addresses that are used come from Bitcoin wallets, which are free to create.
Anyone can download a software wallet that holds Bitcoin (private keys) and will be able to receive and then send Bitcoin to anyone who has a Bitcoin wallet. There are no restrictions on who can use the platform, and it can be used almost anywhere there is internet.
The Bitcoin blockchain operates via specialized computers that are called Bitcoin miners. Via a process that involves complex puzzle solving, new blocks are created on the Bitcoin blockchain, and transactions are approved.
You really don't need to know much about these systems, because the Bitcoin wallets that exist today are very simple to use. Most software-based wallets will feel like any other app, and will simply display how much you have, and let you send and receive Bitcoin, in addition to many other tokens.