|The current object - this|
The latest receiver of a message is called the current object. This is the object on which the latest instance method has been called.
The current object in a C# program execution is denoted by the variable this
This example shows two different uses of this. First, it may be necessary to get access to the current object as such. In the example it is necessary to add the current account to a list of accounts. The second use pertain to methods (and constructors). It is convenient to use the same name for both formal parameters of methods and instance variables of the surrounding class. To disambiguate these, this.x refers to the instance variable named x, and x refers to the local meaning of x.
In this example, any use of a member of the current object is prefixed with this. This is a more radical use of this, which highlights use of members in the current object in contrast to members in other objects.
Read more about the current object in the text book version of this material.