Today you need to remember many passwords. You need a password or passwords for Windows or Linux logon, your e-mail accounts, your websites, your facebook account, your twitter account etc.
You should use different passwords for each account. If you use only one password everywhere and someone gets this password you have a problem.
I prefer KeePass password manager because it is free, open source and it runs in all Platforms. You just put all your passwords in one database, which is locked with one master key or a key file. You only have to remember the master password or select the key file to unlock the database.
KeePass encrypts passwords using AES.
Download KeePass from here.