In modern parlance, the “deep web” and the “dark web” are often used interchangeably despite the fact that they are not synonymous. The confusion is understandable, especially for those that don’t have experience with the nefarious dark web; the deep web, however, has probably been accessed by most internet users.

When a person uses Google or another search engine, they are able to search and index websites thanks to the links that connect various pages on the internet. Search engines sort and rank results based on criteria such as relevancy, inbound links, keywords, and paid advertisements, but only comb through content on the so-called “surface web.” Any content that’s below this surface level is referred to as the deep web and is inaccessible by search engine.

Nevertheless, the content on the deep web isn’t necessarily illicit or dangerous. One of the easiest examples is the use of a public library’s online catalog. While a search within the catalog could offer results from the library’s system, a Google search for the book’s title wouldn’t be expected to return information relevant to your local library because that information is stored in the deep web.

Search engine results can’t tell you what’s in the deep web, because the content stored there isn’t indexed by links. Rather, to access deep web information, you have to search within a specific server, like the library website’s online catalog. Deep web information is incredibly common, in fact almost anytime you use a search bar within a specific website (that isn’t a search engine) you’re accessing deep web data. For the most part, the deep web is harmless since it contains mostly innocuous data and digital archives.

The fact that deep web data isn’t indexed by search engines is a good thing, by and large, since much of the information is sensitive or confidential. Take, for example, being able to search for a person’s bank account number or medical test results without having to access a private portal. Digital security company, Norton, offers a rule of thumb: If you have to log in to one of your accounts by providing a user name, password, or some other type of authentication, the information you access is on the deep web.

Since this data usually requires a login to access it, much of the content on the deep web is relatively safe but that doesn’t mean that accessing that personal information has no risks. The deep web, afterall, is still the internet and practicing safe habits is essential to protecting private information. Using strong passwords is an easy and important way of guarding information, as is making sure that you don’t use an unsecured wireless network while out and about since information transmitted over it could be seen or stolen. Overall, while the deep web is nothing to be afraid of, there is a small sliver of the deep web, known as the dark web, is often associated with illicit criminal activity and should only be accessed by knowledgeable individuals.