It is good practice (and often essential for correctness) to dispose of resources (for example file handles, graphics handles or database connections) when a program no longer needs them. For resources that are used only within a single method, a common idiom is to enclose the code that uses the resource in a try block and dispose of the resource in the try's finally block. This idiom is in fact so common that C# provides a shorter, tidier syntax for it in the form of the using statement.

Given the explicit language support provided in this case, it is more idiomatic to use the using statement in preference to the try-finally technique; it also helps to clearly communicate the intent of your code to other programmers.

In this example a try block is used to ensure resources are disposed of even if the program throws an exception.

The example can be significantly simplified by making use of the using block instead.

MSDN: using Statement.

J. Albahari and B. Albahari, C# 4.0 in a Nutshell - The Definitive Reference, p. 138.