The String.fromCharCode() method is used to create a string from one or more Unicode character codes. Each character in JavaScript has a corresponding numeric Unicode value, and this method helps convert those values back to string.
It accepts one or more numeric values and returns a string created by concatenating the characters corresponding to the provided Unicode values.
You can refer to this link to find the list of Unicode character sets.
In the above code, the Unicode value 65 corresponds to the uppercase letter A.
In the above code, the Unicode values are converted into the string BigBinary by combining their corresponding characters.