These days, there are some pretty distinct styles of wedding photography present in the market. The names for these various styles include: Traditional, Documentary, Photojournalism, Illustrative, Contemporary, Reportage, Candid, and many others. However, when shopping for a wedding photographer you should not assume that the name of the style fits the work. The best way to truly know your photographer's style is to look at their portfolios and albums. I will attempt to provide a very brief summary of the 4 major styles that are most prevalent:
TRADITIONAL
Traditional photographers often refer to their style as "timeless".  The emphasis is to capture romantic poses in a classic style. There is  also much more emphasis on taking posed photos of family and friends. A  traditional photographer often has more interaction with the bride and  groom, which can cause the shoot to take more time. These types of  wedding photographers should be experts in lighting, posing and family  portraits. Some will work off of a so-called "shot list" that the bride  and groom are asked to complete before the wedding.
PHOTOJOURNALISM
In its purest form, photojournalism takes a documentary approach to  wedding photography with emphasis on candid photos with little or no  posing. Other names for this style include Reportage, Documentary or  Candid wedding photography. A true photojournalist will capture emotion,  laughter and the fun present at all weddings. The resulting wedding  album will tell the story of the day in a creative, artistic way.  Photojournalists interact less with the married couple throughout the  day and will usually take less time.
ILLUSTRATIVE
Illustrative photography is a slightly newer style designation, but  it has been around for a while. It contains elements of both  photojournalism and traditional photography. An illustrative  photographer will try to shoot a wedding in a more candid style, but  will improve the circumstances when possible. This may include selecting  the perfect outdoor background to shoot the couple in front of, or  changing the lighting indoors to improve the end result. The  photographer may ask the bride to get dressed close to an open window  with natural light available, but then photograph her in a candid style  with no posing.
CONTEMPORARY
Contemporary wedding photography has only just emerged as a style in  the past few years. This style is about creating high-fashion types of  images. Cover girl types of poses, glamorous make-up and edgy  backgrounds are all part of Contemporary wedding photography. Studio  lighting may be used to create images with impact. A very hands-on  approach is taken with both the bride and groom. They will be instructed  to create very deliberate poses, the types you may see in fashion  magazines. If you are a more reserved type of person, this may not be  the style for you. This type of coverage can be just as time consuming  as Traditional wedding photography, but the results can be spectacular.
It's doubtful that most wedding photographers will neatly into any of one these styles. But when you meet with them, you may hear that they can provide you with bits and pieces of all of the above. The real test is the actual photos each wedding photographer produces. Ask all the photographers you meet where they fit into the above styles, but above all, look at their work!