== Definitions == 

 Some of the definitions here are unclear - maybe someone who knows the datasets better than I do could insert clarifications? As Oxford University's Migration Observatory notes, migration figures are often reliant on terms that are defined very differently by different data-users... 'Resident', for example, needs defining: does it mean 'normally resident' (probably what most people will assume) or does it include foreign students, au-pairs, young people doing gap years, and the like? (This has a significant impact on the data: there are almost half a million foreign students studying in the UK, for example, and I suspect they are included).