Too many people still use passwords that are easy to remember but that makes them easy to break by brute force attacks and easy to guess for password hackers. On the other hand, complex passwords cannot be memorized or recalled easily by most people. These days we need an increasing amount of logins for websites that we use.
Keeping the same password for multiple websites is also not a good security practice. If criminals find one password that means they can access most or all of the websites where you have used the same password.
Password managers can solve all of the above problems to various degrees. You can have one memorable but complex master password and that is the master key to the password manager that stores all your passwords. This means every website where you need a login can have a unique and strong password and you don’t need to memorize all of them because your password manager does that for you.
Some people like to store their passwords in password managers that are built-in browsers. We don’t recommend using those.
Nothing on the internet is one hundred percent hack-proof and password managers are no exception.