The 11+ (also called 11 Plus or Eleven Plus) is a voluntary test taken by Year 6 primary school students who are academically inclined and will go on to a grammar school. It’s called the 11+ test because most students are age 11 in their first year at grammar school when they take the test.
Each education authority, with a grammar school, has its own test which may include these disciplines - English, maths, verbal reasoning, non-verbal reasoning and creative writing. Common Entry tests can differ from school to school as well.