_session_id on www.google.com
About this cookie:
This cookie creates an interim session ID used as an in-session user ID.
There is no specific information about this cookie from this host provider. If you have any information about how this cookie is used by this host, please get in touch.
Related general information about _session_id:
We don’t have enough information about this cookie or the website hosting it to be able to assign it to a category at this time. However, we are constantly updating our knowledge base, so do check back if you need to know more. If it is urgent then get in touch and maybe we can look into it for you.More about cookie classifications.
Third Party Cookies
If the host domain for a cookie is different to the one in the browser bar when it was downloaded, then it is a third party cookie.
They are usually placed in a website via scripts or tags added into the web page. Sometimes these scripts will also bring additional functionality to the site, such as enabling content to be shared via social networks.
For example, if you visit a site that has a YouTube video in one of its pages. This has been included by the website owner, using a piece of code provided by YouTube. YouTube will then be able to set cookies through this code, and know that you have watched that video, or even just visited the page the video is in.
Online advertising is the most common use of third party cookies. By adding their tags to a page, which may or may not display adverts, advertisers can track a user (or their device) across many of the websites they visit.
This allows them to build up a 'behavioural profile' of the user, which can then be used to target them with online ads based around their 'calculated' interests.
Analytics cookies are probably the most common form of persistent cookies in use today.
This protects it from so-called cross-site-scripting (XSS) attacks, where a malicious script tries to send the content of a cookie to a third party website.