A password is a secret set or characters and numbers to something like a computer or website.
Passwords are often paired with usernames or email addresses to identify specific users.
For good security, your passwords should be long, difficult to guess, but easy for you to remember. Your passwords should also be unique to each account or website. That way, if one of your passwords is leaked, all your other passwords are still secure.
Because it's very difficult to create and remember secure, unique passwords, it's recommended to use a password manager. Popular password managers include Bitwarden, 1Password, and LastPass.
You an read more about password managers and online security here.