The getch() and getche() functions in programming languages such as C serve to read single characters from the keyboard. The getch() function reads a character without displaying it, while getche() immediately displays the entered character on the screen.
Both functions do not wait for the enter key to be pressed and return the ASCII value of the entered key. getch() allows the program to continue execution after the key is pressed, while getche() displays the character and then proceeds. Programmers can choose the appropriate function based on whether immediate display is required or not.