If I want to send some of my bitcoin to you, I publish my intention and the nodes scan the entire bitcoin network to validate that I 1) have the bitcoin that I want to send, and 2) haven’t already sent it to someone...
Before owning any bitcoin, you need somewhere to store them. That place is called a “wallet.” Rather than actually holding your bitcoin, it holds the private key that allows you to access your bitcoin address (which is also your public key).
You can pay for them in a variety of ways, ranging from hard cash to credit and debit cards to wire transfers, or even with other cryptocurrencies, depending on who you are buying them from and where you live.
To cut through some of the confusion surrounding bitcoin, we need to separate it into two components. On the one hand, you have bitcoin-the-token, a snippet of code that represents ownership of a digital concept – sort of like a virtual IOU.