Why would I want to hide the Dock or Menu Bar in OS X you ask? That is a very good question. Personally, I don’t hide either one in normal workflow unless I absolutely need every inch of screen real estate for some specific event or project.
Hide The Dock
Some people just like to hide the Dock all the time. All you have to do is roll your mouse over the bottom of your Mac window and it will pop up. I can see this if you are on a laptop especially. Every inch of screen space is like gold. You can hide the Dock in three ways. First and probably the easiest, is to right-click on the divider in the right side of the Dock and select “Turn Hiding On” from the popup menu:
Second, you can hide the Dock in System Preferences. Just click on the “Dock” icon:
And then check the box for “Automatically hide and show the Dock:”
Third, you can use the keyboard command Option+Command+D (⌥+⌘+D) which will hide the Dock. To show the Dock use the same command.
Hide The Menu Bar
I have not used Menu Bar Hide at all, but it is doable. I think I would only hide the Menu Bar as a last resort. To hide the Menu Bar, select the General Pref Pane:
Then check the box for “Automatically hide and show the menu bar:”
Just roll your mouse over the Menu Bar area to get it to drop down for you.
If you need the added screen real estate, hiding the Dock and/or Menu Bar can be helpful.