CHRISTOPHER BARTHOLOMEW: Welcome back. In another video, we discussed the char data type in C which can be used to hold letters, numbers and special characters such as the question or exclamation mark. We know that an individual char has an ASCII value, which is an integer representation of the character. For example, capital letter A's ASCII value is 65. But in C, what do we use for actual words or sentences such as programming, or "C is beautiful?" The answer is a string-- but to be more specific, it is a character string. A character string, or a string, is a sequence of one byte chars that are stored alongside each other in memory. And at the end of any character string in the C language, there's one additional byte that is allocated for a special character-- backslash 0, which is the null termination character. The null termination character is a 1 byte char whose bits are all 0 and it is used to signal the end of a string in memory. This means whether you intend to initialize your string as the sentence "C is fun," or just the word "fun," at the end there will always be a null termination character indicating that the string has ended. To use a string in your program, it is recommended that you initialize your variable as this-- chart star S equals open quote, your string, close quote, semicolon. In this variable definition, variable S points to the first character in our string, which is C. You see, because we now know the entire string is stored sequentially in memory, we can retrieve the string with no problems as we also know where it ends, too-- the null termination character. So have fun. I'm Christopher Bartholomew, this is cs50.