For the duration of the website visit using a session cookie; or
For repeat visits to the website using a persistent cookie.
Cookies are useful for several reasons, including;
Allowing you to navigate between website pages efficiently
Stores your preferences
Improves your website journey
Creates interaction between you and the websites faster and easier
Enables websites to target advertising based on your browsing habits
A cookie is a small file that websites put on your computer when you first visit a website which gives you a unique identification for that site. These cookies allow a website to remember your preferences, what pages you have viewed and what is in your shopping basket.
Turning your cookies off
Even though cookies are harmless, if you do not want target advertisements following your website browsing usage you can turn off your cookie settings and block or delete the cookies that have been automatically set.
However, by doing this it may make some website functions unusable.