Difference Between Strategy Desks and Trading Desks in Fixed Income

I have previously been to a BB's fixed-income trading floor and was able to have a very quick glimpse into the majority of desks. One that really interested me was a strategy desk that seemed to have a smaller team than most of the other desks. Since I didn't have long to speak to everyone there I was wondering what some of the major differences are between a strategy desk and other trading desks such as bonds and MBS.

What does the general work entail? What kind of salary can be expected from analyst to a more senior position? What sort of exit opportunities are there? What sort of backgrounds are hired into these positions?

Any other information or input would be great as well.