The Fourth Year
Those students who achieve a sufficiently high mark in their third year exams can apply to continue studying CS into the fourth year. On graduation, students who complete the fourth year receive a master degree (MEng) in addition to the usual bachelors degree (BA). You don't need to decide whether you wish to study for three or four years when you apply, so if you think there is a possibility that you would like to study for the fourth year, you should ensure you state that you're applying for a four year course on any forms you fill in.
The fourth year is designed to support students who are considering a career in either academic or industrial research. It’s where you get to see the forefront of research in various CS domains. The courses in the fourth year are designed to reflect topical issues in CS and provide you with the opportunity to do a substantial research project that will open doors for you in the research world.
For the full course details for the current year, see the syllabus booklet