Shagun and Dahej

Hi frnds!
Actually I have been a bit confused for a long time with these two words.
I had a notion that 'shagun' means fruits and sweets for the family and relatives and gifts for the bride or groom.
But in 'Yeh rishta...' the families are shown to exchange expensive gifts arranged for each individual on every ritual in the name of 'shagun'.
Then how is it different from 'dahej'?
Plz take no offence. It is just a query to clear my doubts.
Do leave ur comments...