I will give you an example in a hopefully easy manner. It is not 100% what it looks like in the real tech, but the scheme is similar to the following, as far as I know.
Lets say the private key looks like this:
While creating a private key there is a question for a password. As we are all security experts we choose the password:
With this password your encrypted key is created.
abcdefghijklmnopqrstuvwxyz + 12345= nmlkjiopqrstabcdefghuvwzyx
As we see the encrypted key is different from private key. The only way to get back to the private key is combining the encrypted key with the chosen password.
nmlkjiopqrstabcdefghuvwzyx + 12345 = abcdefghijklmnopqrstuvwxyz
Because the encrypted key can’t do anything (with your funds), but is also really hard to remember, we can abstract it with a username for example. Let’s take mine.
Symiaq = nmlkjiopqrstabcdefghuvwzyx // this connection is stored locally on your computer
Going for a login at a wallet, it looks like the following:
Symiaq //interpreted as encrypted key:
-> private key:
abcdefghijklmnopqrstuvwxyz //access to your funds
The encrypted key is your private key combined with a password. Your encrypted key ,with the right password, can be used on any computer to access your funds.
Only when your encrypted key is abstracted with a username, it is only possible on this computer. Because no other computer has the connection between the username and the encrypted key.
When an attacker find out about your encrypted key, he can use your password an access your account.
If I have made any mistakes, please correct me - I’d like to learn