There's no question that Google is the most popular search engine by a mile. It hovers around 90% usage share, making other engines like Bing and Yahoo nearly irrelevant. But while Google powerful, it isn't perfect.

One of the biggest criticisms of the service is how much data Google collects about you from what you search.

Searching the web with Google is a part of almost everyone's daily routine. It's easy to find any information you could want in just a few keystrokes. But have you ever wondered just how search engines like Google actually work?

Let's take a look at the inner workings of Google and see how it knows how to find what you're looking for so efficiently.

Junk mail, also known as spam, is a big annoyance. Whether it's advertisements you never signed up for, poorly-worded scams promising you millions, or inappropriate content, nobody wants it in their inbox.

Though both Gmail and Outlook's built-in spam detection is excellent, sometimes junk mail will slip through.