What does "First Class or 2.1 Honours degree" mean? A PhD position for which I am planning to apply notes:


  Applicants should have (or expect to achieve) a minimum of a First Class or 2.1 Honours degree.


The position is in the UK, but I live in another EU country. What does "First Class or 2.1 Honours degree" mean, and how do I know if I satisfy that condition?

The grades at my university are given as fail, 3, 4 and 5.
The "definitions," such as they exist, of the different degrees, are available from Wikipedia. 

Essentially, "first-class honours" and "2.1 (or 2:1) honours" are the top two categories of honors degrees in the UK system—sort of like the summa cum laude and magna cum laude in American universities. Although the requirements for awarding them appear to be fairly uniform between schools (with the possible exception of Oxford and Cambridge—see dbmag9's comment below), given that each university may have different standards for how they "translate" degrees from other countries, your best bet is to contact the university's international office (or equivalent), to determine if they will consider your degree to be comparable.