Parve or Pareve is a kosher indicator.   Jews who keep kosher do not consume
meat and milk in the same meal (and there are waiting times in between).
Kosher products must thus indicate whether or not they contain any milk
products, or meat products, or neither, in which case they may be eaten with
anything.  The parve products are the ones containing neither milk nor meat.
The kashrut definition of milk is a stringent one, which includes everything
a milk-allergic person needs to avoid.
 
Kosher products are labelled with a number of different symbols, indicating
who supervised the determinitation of kashrut.  One of the most reliable is
O-U, which is a U in a circle.  Unfortunately they don't always specify
pareve explicitly, unless you might expect the product to contain milk or
meat products.  Usually they will specify dairy with a small D beside the
symbol, or meat with the word MEAT, unless it's obvious (i.e. cheese or
chicken soup are not explicitly labled Dairy or MEAT).  So usually a plain
O-U on a product means it's pareve.  Of course kosher meat products are also
100% dairy-free (i.e. some of the Near East rice mixes).  Occaisionally
you will see a Dairy mark on something where you don't recognize any dairy
ingredients -- this occurs when the item is made on a line used for other
dairy-containing products, or too close to a line used for other dairy
products.
 
For this reason kosher cookbooks can be a good source of dairy-free recipes,
especially desserts (to be served after a meat meal).
 
Some kosher marks are not considered reliable.  In particluar a plain K
is not a supervised mark.  Others vary regionally.
 
Hope this helps more than it adds to the confusion,
--Robyn