Passwords are very popular and widespread in modern computer applications. Passwords are no different than locks, since it is safe as long as you (user/password’s owner) are the only one know it. However, if someone else gets a replica of the password, they will be able to gain access to that place or application.
Previously, I have explained the requirements behind choosing a strong password. In 2010, a study was performed on several websites containing over 32,000,000 passwords shows that the passwords had previously been leaked on the web. This is due to the online attacks, which were performed by the attacker by selecting a set of targets and applies several guesses.
Eventually, try to avoid the blacklist passwords, which contain the popular and unacceptable passwords. For example, Twitter was once compromised due to an administrator’s password being “happiness”.