__utma
This cookie is what’s called a “persistent” cookie, as in, it never expires. This cookie keeps track of the number of times a visitor has been to the site pertaining to the cookie, when their first visit was, and when their last visit occurred. Google Analytics uses the information from this cookie to calculate things like Days and Visits to purchase.
__utmb and __utmc
The B and C cookies are brothers, working together to calculate how long a visit takes. __utmb takes a timestamp of the exact moment in time when a visitor enters a site, while __utmc takes a timestamp of the exact moment in time when a visitor leaves a site. __utmb expires at the end of the session. __utmc waits 30 minutes, and then it expires. __utmc has no way of knowing when a user closes their browser or leaves a website, so it waits 30 minutes for another pageview to happen, and if it doesn’t, it expires.
__utmz
Keeps track of where the visitor came from, what search engine you used, what link you clicked on, what keyword you used, and where they were in the world when you accessed a website. It expires in 15,768,000 seconds – or, in 6 months. This cookie is how Google Analytics knows to whom and to what source / medium / keyword to assign the credit for a Goal Conversion or an Ecommerce Transaction. __utmz also lets you edit its length with a simple customization to the Google Analytics Tracking code.
Dynamicweb, Dynamicweb.SessionVisitor
Contains a Dynamicweb assigned session id of the current visitor to control logins, carts and other visitor context dependent information. This cookie is used instead of regular sessionids that can expire if the user closes the browser and opens again. The sub cookie VisitorDynamics keeps score information about what type content the current visitor has been seeing. This cookie expires 30 minutes after the users last activity (pageview).
_vwo_uuid_v2
This cookie name is associated with the product Visual Website Optimiser, by USA based Wingify. The tool helps site owners measure the performance of different versions of web pages. This cookie ensures a visitor always sees the same version of a page and is used to track behaviour to measure the performance of different page versions.
ASP.NET_SessionId
When a user browses to the website, a unique session ID will be associated with the user to keep track of any information that is stored for that session. This information is stored on the Web Server (known as storing information in session) and is identified via a GUID. The GUID is stored in the Cookie (known as the ASP.NET_SessionID) and is essential for any ASP.NET website to function correctly. If nothing is put in the session however, no cookie will be sent to the browser so this cookie will only be created when it is needed. This cookie will expire at the end of the session which is defined in the application configuration (which is normally around 20 minutes)