The bridal portraits are typically 1-2 months before the wedding day in full wedding day attire. Hair, makeup, jewelry, veil, shoes, bouquet, and of course, the dress. These Portraits are always kept a secret until after the wedding ceremony. Generally a large portrait or two from the session is displayed at the reception near the wedding cake or guestbook. In many cases the large photo is given as a gift to the Mother of the Bride after the wedding, with smaller photos being given to the Groom and the Father of the Bride, as well. 
A bridal session can provide many benefits, including:
Time: You can create the images you want without sacrificing your wedding day timeline.
Trials: You can try your hair, makeup, jewelry, bouquet, and dress before the wedding.
Wear your dress more: You can wear your dress more than once.
More photos: You can get more photos.