“Not provided” in Google Analytics refers to organic search traffic that comes from SSL searches or logged-in users, where the specific search queries are not passed to GA for privacy and security concerns.
When a user is logged in to their Google account and performs a search, their search query is encrypted using SSL (Secure Sockets Layer) technology. This means that the search terms are not visible to third-parties, including Google Analytics. Instead of showing the specific search terms in Google Analytics, Google reports this traffic as “not provided.”
This SSL encryption of search queries was introduced in 2011 as a security measure to protect users’ private information, such as their search history and personal data, from being intercepted by third parties. As a result, website owners and marketers have limited visibility into the search terms that are driving traffic from these logged-in users.
However, it’s important to note that the SSL encryption only applies to users who are logged in to their Google account at the time of the search. If the user is not logged in or uses a search engine other than Google, their search terms will still be visible in Google Analytics.