This is how Subtractive Modeling takes place
You must begin with a Solid Feature, then use Cut to remove "Material"
Works almost identically to Extrude with exception that you'll now have the options to cut Through All (or Though All Both if you'd like to go in both directions automatically)
If instead of cutting everything contained within the selected profile you'd like to keep that, check the Flip Side to Cut box
Imagine a cookie-cutter but instead of removing the cookie, you remove the flash
Click the model that Requires a Cut Feature