It depends on the language, but the charAt method will usually return the character at a certain position. Keep in mind, computers start counting at 0, so if I do "Hello".chatAt(0), 'H' would be returned.
The CharAt is a string method in computer programming. It generally takes one argument, and returns the character that is at that location in a zero indexed string. "charles".CharAt(3) would return 'r', as r is the 3rd letter in the zero indexed string.