What's the equivalent of windows explorer? The documentation says that Finder replaces windows explorer.  However I have gone to my home directory in a terminal and created a directory with

mkdir temp


How can I browse this directory using Finder?  At the moment I cannot see it at all.
You can access the finder via the Dock:


When in the terminal, you can open the current directory in the terminal via:
open .


Here's a finder window. I've created the directory ~/temp like you said.

You can also ⌘-click the info icon at the very top to see the path: