First of all, you must know that ls is a command that you use in the terminal to list files in the current directory. The Character “*” has a especial meaning for shell. Specifically this character means match any characters in a filename. For example if you put: ls *hello in the terminal, you will list any filename that end with the characters “hello” in the current directory. So, the characters .c meaning you will list filenames that ends with “.c”