The internet, as the saying goes, is like an iceberg. You’ve almost certainly heard this before, or even seen one of the many, many graphics representing this metaphor. Whilst it is old as the hills (or glaciers?) it is a relatively simple way of describing the strata of the internet, if slightly clumsy and archaic.
In this document I will briefly outline, as simply as I can, what is meant by ‘open web’, ‘deep web’ and ‘dark web’ and the key differences between them. Come with me, to the imaginary library of all human knowledge, that is the internet.

The Open Web, or the bookshelf

If we consider the internet to be a library, then the open web can be considered to be the books on the shelves; in essence, you can see them just by looking with your eyes. A more technical answer would be that the open web is anything that can be indexed by a search engine and accessed by a conventional web browser. This information is readily available and easy to access.

The Deep Web, or book pages

Carrying on with our library analogy, the deep web could be considered the pages within the books; still readily available to you but not immediately visible; some interaction is required to see the information. More technically, the deep web can be described as websites viewable through a conventional web browser but not indexable by a web browser. Examples of this include news articles behind paywalls (such as NYT articles), hotel prices (as you need to enter your search criteria), or a forum where you need to log in to see the posts on the forum.

The Dark Web, or microfiche

The dark web, however, is less accessible. Like a microfiche archive, you need special tools to view it; additionally you need to know exactly what you are looking for as you cannot simply browse the 'bookshelves'. On a more technical level, the dark web is a network of websites that are not indeced, and require specialised software to access. The most commonly known of these is TOR (The Onion Router), but there are other examples such as I2P (The Invisible Internet Project).

The information contained in this article is provided for informational purposes only and does not constitute professional advice and is not guaranteed to be accurate, complete, reliable, current or error-free.