Most of us use the top layer of the internet, the so-called surface web – also called the visible, public, or open web – on a daily basis. This includes everything that can be easily found through search engines like Google or Bing.
How Google indexes the web
Find out by watching this short 5-minute video.
Source: Google.
Beneath the surface web lies a much larger, hidden layer known as the deep web. This includes millions of pages containing financial records, academic databases, private social media content, subscription-only articles, and other data that is not publicly accessible. The deep web consists of content that search engines can’t index – meaning you won’t find it through a Google search. You access deep web content when you log into your email, use online banking, or search within a website’s internal database. These pages are hidden behind login forms or search boxes, preventing search engine crawlers from accessing them.
Additional examples of deep web content include:
The dark web is a small portion of the deep web that is intentionally hidden and requires special software to access. While some people use the dark web for privacy-related purposes – such as whistleblowing or political activism – it is also known as a hub for illegal activities, including black market trading (e.g., drugs and weapons), the distribution of illegal content, and services related to fraud and identity theft.
Open access is a global academic movement that promotes free and unrestricted online access to scholarly research. Unlike the traditional subscription-based publishing model – where libraries or individual readers pay for access – open access ensures that research is available to everyone, without financial or legal barriers. When content is open access, it is often marked with the open access icon .
How can researchers make their work open access?
Self-archiving (green open access)
Researchers can deposit a version of their article in an institutional repository. This is usually the postprint — the peer-reviewed manuscript accepted for publication but not yet copy-edited or formatted. An institutional repository is a digital archive maintained by universities to store and share research. This makes the work freely accessible, often after an embargo period set by the publisher. Self-archiving is a cost-effective and widely used open access route.
Researchers can publish their final, peer-reviewed articles through gold open access, where articles are made freely and permanently available to all readers immediately upon publication. Gold open access journals typically charge authors a fee to cover publishing costs.
Alternatively, authors can publish in hybrid journals – traditional subscription-based journals that offer the option to make individual articles open access for a fee.
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by Tilburg University.