Open a Finder window (Finder > New Finder Window) and then choose View > Show Path Bar. The Path Bar appears at the bottom of all your Finder windows, showing the complete path from your computer to the current folder.
At first glance, that’s all the Path Bar does. But as Sharon Zardetto points out in her Macworld article: Five overlooked abilities of the Finder’s Path Bar, it can do a whole lot more.