Here’s the problem
The bad guys steal a large password list. ok. no big deal you think if they access my ****.com account. BUT – Since you use the SAME password on about a few dozen websites, the bad guys now have access to lots of your accounts. not good.
SOLUTION – do NOT RE-USE passwords. Use a different password for each different website.
PROBLEM – How the heck do we remember dozens of different complex passwords and what websites they go to?
SOLUTION – Use a password manager. These programs/services keep your ‘list’ of usernames/passwords and make it easy to keep different passwords. Many automatically fill in the login data for you.
One I really like is Last Pass. It has a good FREE version and works with all of your operating systems, mobile devices and browsers.