LastPass is a password manager. But, it's not just any old password manager. It encrypts your passwords locally on your computer and then uploads the encrypted data to a secure site online. That means that you can access your passwords from any computer with an Internet connection.
What I love about LastPass is that I can easily install the browser add-on/plug-in/extension into IE, Firefox and Chrome on all of my computers and have my passwords available in any browser on any of my computers. How convenient!