Main types of cookies
Transient (or per-session) cookies
These only exist for the duration of your site visit and are deleted on exit. They recognise you as you move between pages, for example recording the items you add to an online shopping basket. These cookies also help maintain security.
Persistent (or permanent) cookies
These stay on your machine until they expire or are deleted. Many are built with automatic deletion dates to help ensure your hard drive doesn't get overloaded. These cookies often store and re-enter your login information, so you don't need to remember membership details.
We use both cookies
Additionally, cookies can be first- or third-party cookies. First-party cookies are owned and created by the website you're viewing. Third-party cookies are owned and created by an independent company, usually a company providing a service to the owners of the website.
Internet cookies are common and do not harm your system - they just store or gather site information. They help you do things online, like remembering login details so you don't have to re-enter them when revisiting a site.
- Gather customer journey information on our public site only
- Temporarily store input information in our calculators, tools, illustrations and demonstrations
- Store details of your marketing, product preferences to improve our targeting and enhance your journey through our sites and partner sites
- Evaluate our sites' advertising and promotional effectiveness (we own the anonymous data collected and don't share it with anyone)
To enable or disable cookies, follow the instructions provided by your browser (usually located within the 'Help', 'Tools' or 'Edit' facility). Alternatively, an external resource is available at All about cookies providing specific information about cookies and how to manage them.