A cookie is a small text file implanted by an online provider (for example, a website operator or an online advertising network) on the hard disks of visitors to the site (often without their knowledge). Cookies collect information about internet users, such as their names, addresses, e-mail details, passwords and user preferences. While cookies and the information they transmit may not identify a living individual on their own, they may be able to do so in combination with other information held by the online provider or a third party.

Different types of cookies

There is a general distinction between session cookies and persistent cookies and between first-party cookies and third-party cookies.

Session cookies

Session cookies are cookies that expire at the end of a browser session, that is when the user exits the browser. They allow websites operators to link the actions of users during a single browser session to allow them to use the website most efficiently. For example, session cookies enable a website to remember that a user has placed items in an online shopping basket. As these cookies are not usually stored beyond the browser session, they are usually considered less privacy intrusive.

Persistent cookies

In contrast to session cookies, persistent cookies are stored on the user's equipment between browsing sessions. They therefore enable the website to "recognise" the user on his return, to remember the user's preferences and to tailor services to them. The may also be used to track the user's browsing activity across different websites and to build up a detailed profile of his browsing behaviour for targeting advertising. For this reason, persistent cookies are generally considered to be more privacy-intrusive than session cookies.

First-party cookies

First-party cookies are planted by the website which a user visits itself. This involves assigning a unique identity to the user by setting the cookie to either the user's browser and/or his hard drive with a view to tracking the user's journey on the website. First-party cookies are commonly used by website operators for session management, personalisation and recognition purposes where the information transmitted by the cookie is later combined with the personal information the internet user has supplied to the provider in the course of a sale or other contact. In these cases, a user's cookie is retrieved each time he visits the site which planted it, making it unnecessary to re-enter registration data on each visit, and enabling the user to benefit from features such as Amazon's 1-click shopping and the ability to store items in an electronic shopping basket between visits. Although cookies provide internet users with some benefits, they also enable online providers to build profiles of individual users, their online behaviour and their interests. The website may then make specific recommendations to the user on goods and services depending on the information collected in this way. For example, the books, CDs, DVDs and other products that are displayed to a user on the home page of online retailer Amazon will largely be determined by the user's previous purchases and their on-site browsing habits. The user profiles created in this way are also commercially valuable, and online providers often sell the information collected in this way to third parties for the purpose of marketing. Users can block first-party cookies by adjusting their browser settings. However, in some cases this may lead to a loss of functionality of the site visited.

Third-party cookies

Third-party cookies are cookies planted by parties other than the owner of the website a user visits. In practice, many website owners will reserve visual space on its website in return for a fee paid by an advertising network provider. The renting out of website space for the purposes of behavioural advertising is an increasingly essential part of many website operators' monetisation strategies.

The advertising network provider will normally use the spaces it rents on different websites to:

• Plant a cookie on the user's browser or hard drive when he first visits a website that is part of its advertising network.
• Recognise any former visitor who returns to that website by the cookie previously planted on his equipment.
• Recognise any user who has already visited any other website that is a partner of the advertising network by the cookie planted on his equipment by the first website he visited.
• Serve a particular advertisement to the user in real-time based on his interests (as identified in the profile created for him based on his journey across different partner websites).

As with first-party cookies, users are able to block third-party cookies through their browser settings.

Cookies are NOT viruses

COOKIE NAME	DECRIPTION
PHPSESSID	This cookie is set as a result of a user session being created in PHP and is driven by a unique ID, a cryptographically random number. This unqiue ID is stored on the client side for the lifetime of a session. Without this ID would affect the functionality of our site, meaning if you were to add items to your shopping basket for example, the site would not remember what was added and thus you then would not be able to place an order with us.
__utma	This cookie is typically written to the browser upon the first visit to our site from that web browser. If the cookie has been deleted by the browser operator, and the browser subsequently visits your site, a new __utma cookie is written with a different unique ID. This cookie is used to determine unique visitors to our site and it is updated with each page view. Additionally, this cookie is provided with a unique ID that Google Analytics uses to ensure both the validity and accessibility of the cookie as an extra security measure.
__utmb	This cookie is used to establish and continue a user session with our site. When a user views a page on our site, the Google Analytics code attempts to update this cookie. If it does not find the cookie, a new one is written and a new session is established. Each time a user visits a different page on our site, this cookie is updated to expire in 30 minutes, thus continuing a single session for as long as user activity continues within 30-minute intervals. This cookie expires when a user pauses on a page on our site for longer than 30 minutes.
__utmc	This cookie is no longer used by the ga.js tracking code to determine session status. Historically, this cookie operated in conjunction with the __utmb cookie to determine whether or not to establish a new session for the user. For backwards compatibility purposes with sites still using the urchin.js tracking code, this cookie will continue to be written and will expire when the user exits the browser.
__utmz	This cookie stores the type of referral used by the visitor to reach our site, whether via a direct method, a referring link, a website search, or a campaign such as an ad or an email link. It is used to calculate search engine traffic, ad campaigns and page navigation within your own site. The cookie is updated with each page view to our site.
__utmv	This cookie is not normally present in a default configuration of the tracking code.
__utmx	This cookie is used by Website Optimizer and only set when the Website Optimizer tracking code is installed and correctly configured for our pages. When the optimizer script executes, this cookie stores the variation this visitor is assigned to for each experiment, so the visitor has a consistent experience on our site.
LivePersonID	This cookie is used in conjunction with the HumanClickKEY cookie (described below) to gather usage data related to a visitor's visit to a LivePerson customer's website. The information gathered is essential for determining whether LivePerson's hosted services should launch on the visitor's browser. This cookie is set when LivePerson's services initiate monitoring. Disabling or blocking this cookie may limit or prevent the visitor from receiving assistance or offers from the customer's website via LivePerson's services. This cookie is a persistent cookie that remains on the visitor's browser for up to 12 months after which time it is automatically deleted.
HumanClickSiteContainer ID_<SITEID>	This cookie is used by LivePerson with respect to its largest customers in order to allow LivePerson to distribute usage of its services across a cluster of servers (for load balancing purposes). This cookie is set when LivePerson’s services initiate monitoring on the applicable customer’s website. Disabling or blocking this cookie may limit or prevent the visitor from receiving assistance or offers from the customer’s website via LivePerson’s services. This cookie is a session cookie that is automatically deleted when the visitor closes his or her browser.
HumanClickKEY	This cookie is used to identify a visitor’s session on a customer’s website and monitor the pages viewed by the visitor on the customer’s website, the time spent by the visitor on pages of the customer’s website and other usage data related to the visitor’s visit to the customer’s website. This cookie is set when LivePerson’s services initiate monitoring. Disabling or blocking this cookie may limit or prevent the visitor from receiving assistance or offers from the customer’s website via LivePerson’s services. This cookie is a session cookie that is automatically deleted when the visitor closes his or her browser.
HumanClickACTIVE	This cookie (sometimes referred to as an acceptance test cookie) is used to determine whether a cookie can be set on a browser. This cookie is set when LivePerson’s services initiate monitoring. Disabling or blocking this cookie may limit or prevent the visitor from receiving assistance or offers on the customer’s website via LivePerson’s services. This cookie is a persistent cookie that expires after 24 hours.
HumanClickCHATKEY	This cookie is used for security purposes to identify each LP Chat and LP Voice communication session. This cookie is set when the visitor to the customer’s website requests an engagement with in a chat or voice session with the customer. Disabling or blocking this cookie may limit or prevent the visitor from receiving assistance on the customer’s website via LivePerson’s chat or voice services. This cookie is a session cookie that is automatically deleted when the visitor closes his or her browser.
HumanClickACTIVE	This cookie (sometimes referred to as an acceptance test cookie) is used to determine whether a cookie can be set on a browser. This cookie is set when LivePerson’s services initiate monitoring. Disabling or blocking this cookie may limit or prevent the visitor from receiving assistance or offers on the customer’s website via LivePerson’s services. This cookie is a persistent cookie that expires after 24 hours.
uid/uit	Uniquely assigned machine-generated user ID
psc/uvc	These cookies are used in recording user sharing and social activity

Here are some links you might find useful to more information about cookies:

allaboutcookies.org

ico.gov.uk

civicuk.com/cookie-law/browser-settings