Linguistics question- prestige vs convergence

[Keysi]

I've been reading a lot about overt and covert prestige from Labov's experiments in the department stores and convergence and divergence from Howard Giles' Communication Accommodation Theory and was just wondering if someone could explain the main difference between the two as they seem very similar. And if you could point out which situations it would be more appropriate to use one as an explanation over the other?

 

Cheers in advance.

[Alan Watson]

Which situations do you have in mind ?

[Keysi]

Well I'm gonna be analysing them in my English language A level exam situation

 

The subjects covered are conversation analysis, language Aquisition and sociolinguistics.