15 Section 2 INTRODUCTION cyber security at all levels for our collective benefit and will be the basis on which the UK engages internationally to promote good internet governance. 2.11. In this strategy, ‘cyber security’ refers to the protection of information systems (hardware, software and associated infrastructure), the data on them, and the services they provide, from unauthorised access, harm or misuse. This includes harm caused intentionally by the operator of the system, or accidentally, as a result of failing to follow security procedures. 2.12. Consistent with our assessment of the challenge we face and building on the achievements of the 2011 strategy, this document sets out: • our updated assessment of the strategic context, including the current and evolving threats: who poses the most serious threat to our interests, and the tools at their disposal; • a review of vulnerabilities and how these have developed over the last five years; • the Government’s vision for cyber security in 2021 and the key objectives to achieve that goal, including guiding principles, roles and responsibilities, and how and where government intervention will make a difference; • how we intend to put our policy into practice: setting out where the Government will lead and where we expect to work in partnership with others; and • how we intend to assess our progress towards our objectives. National Cyber Security Strategy 2016