Switching back and both from the front and back end can be done many ways:
Once you’re logged into your website you’ll be re-directed to the Dashboard. This is like the home page of the back end of WordPress. From here you an access the complete menu on the left.
You’ll also see a black bar along the top of the page with it’s own menus. This black bar is fixed to the top of the page and remains visible to you on the front end of your website (what visitors see) as long as you remain logged in. The menus in this bar allow you to easily toggle back and forth from the front end of a page, category or post, to the back end for easy editing.