You will see that the address bar auto-complete drop-down list looks much more manageable now. If you wish, you can also delete the AutoComplete history here or Manage Passwords.

So if you’re searching for Hewlett-Packard, after typing the first few letters of the company name you can either highlight the search term in the Autocomplete drop down list or keep typing ...

They incorporate aspects of both drop-down lists and text boxes so that users can start typing a word and Excel will automatically complete it based on the combo box's properties.

Aauto-complete in Office Outlook lets you see the old email addresses in the drop-down that you have used. But you can disable it & remove them if you want to.