It takes an input string (input), splits it on the space character (input.Split(' ')) (presumably to get the number of “words”), adds 1 to the .Length of the resulting array (not sure why), converts that number to a binary string (Convert.ToString(int, 2) will convert the int to a base-2 number and return it as a string), then pads the left side of the string with the 0 character until it’s 8 characters long (.PadLeft(8, '0')).
My guess is that this might be used in some kind of encoding/decoding algorithm(?).
Here it is in action:
var inputStrings = new List<string>
{
    "one",
    "two words",
    "this is three",
    "this one is four",
    "and this one has five"
};
foreach(var input in inputStrings)
{
    var result = Convert.ToString((input.Split(' ').Length + 1), 2).PadLeft(8, '0');
    Console.WriteLine($"{input.PadRight(22, ' ')} = {result}");
}
Console.Write("\nDone!\nPress any key to exit...");
Console.ReadKey();
Output
solved Programming with C# console application
