Random password generator: How to generate secure passwords

We use passwords to protect all private information. Your online accounts, computer files, and personal information are safe only if you have strong passwords to protect them.

What makes a password strong? How to measure the password strength in meaningful way?

The strong random passwords are essential for any password-protected system, service or account. However, it is not an easy task to create such passwords and there are many wrong ways to do it without even noticing that the created passwords are weak.