What does the 'using' directive in code refer to?

In C#, the using directive is used in two main contexts:

1. Namespace inclusion — allows using types from the specified namespace without needing to write the full name.

using System.Text;

StringBuilder sb = new StringBuilder();

2. Ensuring proper resource disposal — the using statement guarantees that the Dispose() method is called on an object implementing the IDisposable interface after the block ends.

using (var stream = new FileStream("file.txt", FileMode.Open))
{
    // Working with the file
} // Here, stream.Dispose() is called automatically

Thus, using helps manage dependencies and resources in the code.