At the end / in the end

What is the difference between the two expressions ‘at the end’ and ‘in the end’?

‘at the end’ has different meanings:

1) the end of a physical location (at the end of the street)

2) a metaphorical end (at the end of the story)

3) the end of a period of time (at the end of the century)

‘in the end’ is an adverb phrase which means ‘finally’. E.g. We waited for an hour and, in the end, we went without her.

http://www.bbc.co.uk/worldservice/learningenglish/language/askaboutenglish/2009/06/090901_aae_end_page.shtml