How the fuck can we owe ireland more than they owe us?
They explain some of the quirks in the numbers in the sidebar text.
but who do we actually owe the money to,who lends it? banks? goverments?
The charts show all the money owed by one country to another, not just the Government debts. So if a UK bank had borrowed money from a US bank, say to fund a mortgage offer, then it shows as a UK to US debt. Hence our total foreign debt is €7.3tn and our total Government debt is €1.4tn (which isn't all foreign debt).
There are other related articles on the BBC website (mainly the blogs) which explain why despite what those figures may suggest, countries like Italy and Spain are really in the shit and we aren't.