Yes there are many terms which people confuse with each other and you have specified some of them and use them individually.Like keys are of two types public and private and private keys are used to sign the transaction and prove ownership of funds while public keys are visible.So thanks for sharing it man and bumping it up for newbies and us to check it once.
You're right, a private key, as the name suggests, is confidential information that should never be shared with anyone, except for rare cases such as matters of inheritance or educational purposes. A private key allows you to unlock certain UTXOs in a blockchain, namely those that contain specific coins sent to a specific address that corresponds to a given private key. A public key is another matter. While its name suggests that you can safely share it with the public, you don't necessarily need to do that. The basic rule is that the less information you give out, the better off you and your coins are. Also, I'd like to add to your thoughts about transaction verification. A private key is used to produce a digital signature which in turn is used to authorize your spending. It is a way to prove that you actually have a right to spend without revealing private information. But in order to prove you do have this private information, you also have to provide your public key. Your public key is used to verify that your signature is valid and you actually own a private key. A public key is not visible until you make it visible by spending your coins.
