You might have noticed a mode in your browser called "Private Browsing" or "Incognito Mode". The name may vary depending on your browser of choice. But the features it offers remains the same.
When you open a browser window in private or incognito mode, the browser stops storing all the various stuff it usually stores about sites as you putter around the information superhighway. Typically, this stored stuff includes things like the site's URL, text you may have typed into the site's forms, and cookies from websites and all the pages you have visited will not be logged in History tab.
Here are some of the most common reasons people are using Incognito Browsing.
1. Signing into multiple email accounts at once
You could set up different browser "profiles" to switch between email accounts within one browser, but incognito mode is the quick and easy way of doing this on the fly — no setup required.
2. Watching weird videos
Again, though there is another way to pause videos getting added to your YouTube history (within YouTube settings themselves), the incognito mode is quick and easy.
3. Using computers that aren't yours
If you need to log into your email or your banking account or whatever on a computer away from home, just pop open incognito mode to provide a layer of protection against your passwords or user info being saved to that computer (not totally infallible, that computer could have keystroke logging software on it or something, but it helps).
4. Booking travel
If the airlines are going to play pricing games with us, then we're going to play games with them right back, dammit (though private browsing for a lower fare may or may not actually work).
5. To look like a fresh visitor
If you are tinkering with the code for a website, you may want to prevent your browser from saving ("caching") the site in order to force it to reload the potential changes each time. Also, since Google customizes search results, incognito mode can give you a clean slate of Google search results rather than ones affected by your past Googling.
