Partial Class

Partial Class is New functionality that is included in visual studio.net 2005.This New functionality help you to split a single class into multiple partial classes.This partial classes can be diffrent individual files.
Its nothing but the small part of big class.you can declare by following syntax
partial class Rajat
private intI as integer = 4,
private intJ as integer = 3
End class
public class Rajat
private intSum as integer
public sub sum()
intSum = intI + intJ
end sub
End class

Here intJ,intI are define in partical class of rajat which is used in public class rajat.