Cookie Control has been developed to help webmasters comply with EU legislation on privacy. If you've visited a website sporting Cookie Control, it's because the webmaster cares enough about your privacy to tell you how cookies are used on their site, and how to manage cookies in future.
Cookies are small files stored on your computer. Typically they're used by websites to do things like maintain your preferences, identify your session, store items in shopping carts and for storing authentication status. These files cannot harm your computer, but they can potentially be used to track some of your browser activity, and in the hands of hackers, can give away some personal data.
In most cases cookies are harmless, and you will only diminish your browsing experience by disabling them using the instructions below. In some cases websites will not work if you disable cookies in your web browser.
If it's just those creepy ads that seem to know what you've been looking at that bother you, you may want to consider opting out using Ad Choices. Ironically of course, your opted-out status will be stored using a cookie. And if you clear your cookies, this status will be lost.
Most of the browsers below allow you to opt out of third party cookies, while leaving first party cookies switched on. Third party cookies are issued by web services other than the website you're looking at at the time, and can allow those web services to track you as you browse from site to site. Facebook and Google do this routinely, as do a number of other advertising networks.
If you just want to avoid the creepiest, most invasive cookies but leave most other stuff in working order, it can be a good option to turn off third party cookies using the browser settings below.