Once you have added a site to your LastPass account, an entry will be stored in your LastPass Vault. You can view the saved site’s details at any time by clicking the ‘Edit’ link next to the site.
If you decide to update your username or password for a particular site, LastPass will log the change. The next time you launch the Edit dialog box from your Online Vault, you will see a ‘History’ link next to the password and/or username fields:
This allows you to easily track changes to your accounts, especially for those which you should make an effort to change the password on a regular basis:
*Note: If you edit an existing entry in your Local Vault, you will see an option to view username and password histories. Clicking these links will take you to your Online Vault and History dialogs.