Types is a powerful tool for controlling how Windows handles individual file types, including their icons, the programs used to process them, their Explorer menu extensions, and more.
Launch Types and you'll see the icons for all the file types registered on your PC. Double-click one of these to access the options you can perform on it.
If you want to change the icon for this file type, for instance, click the Icon tab, then the Browse button, and select the file for whatever icon you'd prefer.
Clicking the Menu tab reveals any menu options associated with this file type. You're able to choose which apps will open, edit or print the files. Or, if there's an Open option belonging to an app you no longer have installed, say, then you can delete that here.
Clicking the Class tab allows you to change the name of this file type, set a linked class or a "perceived type": you can tell Windows that a particular file type should be treated as a text document, say.
And the Other tab includes an Extension Visibility option that can tell Windows to always, or never show the extension for that file type, regardless of its Explorer settings.