Carriage return means to return to the beginning of the current line without advancing downward. This is commonly escaped as “\r“, abbreviated CR, and has ASCII value 13 or 0x0D.
Linefeed means to advance downward to the next line. Used as “newline”, it terminates lines (commonly confused with separating lines). This is commonly escaped as “\n”, abbreviated LF or NL, and has ASCII value 10 or 0x0A.
Form feed means advance downward to the next “page”. It was commonly used as page separators, but now is also used as section separators. Text editors can use this character when you “insert a page break”. This is commonly escaped as “\f”, abbreviated FF, and has ASCII value 12 or 0x0C.
Backspace moves the active position to the previous position on the current line. If the active position is at the initial position of a line, the behavior of the display device is unspecified. This is commonly escaped as “\b”
As control characters, they may be interpreted in various ways. The most common difference is lines end with CRLF on Windows, NL on Unix-likes.