The GDPR is a set of EU laws that come into affect on May 25th 2018.
The purpose of the GDPR is to provide a set of standardised data protection laws across all the member countries. This should make it easier for EU citizens to understand how their data is being used, and also raise any complaints, even if they are not in the country where its located.
Despite the UK’s exit from the EU it is still expected to affect British businesses (GDPR and Brexit for more info).