Detailed but Simplified

In super simple terms, sending and receiving crypto is like signing a message with your private key and sharing it with everyone, so they know it's from you. Then, your friend can use your address (public key) to check your signature and get the digital money you sent!

When you want to send digital money to your friend, you use your private key to create a special code, like your signature, on a message saying how much you want to send and where it's going. This signature is unique to you and shows that the message came from you.

Then, you share this message, along with your public key (your address), with everyone on the internet. This way, they know it's from you because of your unique signature, and they can see where the digital money is going because of your public key.

Your friend, who has their own private and public keys, can use your public key to check your signature and make sure the message is really from you. Once they're sure it's from you, they can use their private key to unlock the digital money and add it to their account.

Interesting info: These people that hold the blockchain ledger and they are able to verify that you actually hold the funds you want to send, are not humans! They are computers, called nodes, connected at the blockchain network. They are also making a small profit for each transaction transmitted on the network. This fee is called transaction fee (tx fees), and the actual cost depends on the network congestion.