Nikah is the actual marriage in Islam. It is very simple process.
Nikah is considered to acceptance to go in nuptial relationship by both Boy and Girl in presence of at least two witnesses and Quazi(Judge).
Quazi asks both bride and groom separately that he / she is getting married to the such and such person. Does he / she agree?
He / She has right to say Yes or No.
When a bride comes to the her in-laws home, a grand feast called Dawat-e-Walima is thrown by the groom.
As per the Quranic guidelines it is the groom who has to invite his all friends and relatives to join the feast.
Usually Walima is conducted within a few days of completion of Nikah. In Islamic literature we find no sign of feast being organized by bride's side.
Before or at the time of Nikah an amount called Mehar is agreed to be given by the groom to the bride for this marriage. This amount is called Mehar
Female has full right to spend from this amount. This amount is considered to be the the gift or compensation or protection for her future life.
Mehar payment is mandatory.
In fact there is no concept of Baraat with lot of crackers and band instruments. Islamic weddings are very simple in fact.
All it requires is to get the congregation of friends, relatives who will be the witness of a Nikah and will pray for the newly wed couple to have a better life.
Groom side will distribute sweets / dried dates on this occasion.