The Cookie Law is a new piece of privacy legislation from Europe that requires websites to obtain consent from visitors to store or retrieve any information on a computer or any other web connected device, like a smartphone or tablet.
It has been designed to protect online privacy, by making consumers aware of how information about them is collected by websites, and enable them to choose whether or not they want to allow it to take place.
It started as an EU Directive that was adopted by all EU countries on May 26th 2011. At the same time the UK updated its Privacy and Electronic Communications Regulations, which brought the EU Directive it into UK law.
Each EU member state has done or is doing the same thing. Although they all have their own approach and interpretation, the basic requirements of the directive remain the same.