Explain what re-throwing an exception means in error handling?

Re-throwing an exception in C# means that within a catch block, we catch an exception, possibly perform some additional processing (such as logging), and then throw the same exception again so that it can be handled at a higher level.

This is done using the throw; keyword without specifying an exception, to preserve the original call stack.

Example:

try
{
    // code that may throw an exception
}
catch(Exception ex)
{
    Console.WriteLine("An error occurred: " + ex.Message);
    throw; // re-throw the exception
}

This approach is useful when you want to add additional error handling but do not suppress the exception.