the GenerateRandomString() method takes an integer argument length that specifies the length of the random string to generate. The chars variable defines a character set that includes upper and lowercase letters and digits. The Random class is used to generate a random index into the character set for each character in the random string, and the resulting characters are concatenated into a new string.

The Enumerable.Repeat() method is used to repeat the character set length times, and the Select() method is used to randomly select a character from each repeated character set. The resulting characters are combined into an array using the ToArray() method, and then passed to the string constructor to create the final random string.

Note that you need to include the System.Linq namespace to use the Enumerable class.