The terms “line feed” and “carriage return” refer back to the days of typewriters and teletypes. Typewriters had carriages that had to be returned to the left most position to begin typing the next line; line feed was for later, more automated machines that had the typing head moving and not the carriage, to indicate to return to the left go to the next line. These symbols made it into modern computer text technology/terminology, “cr” being carriage return and “lf” meaning line feed, both indicating the end of a line and the start of the next one (as computers don’t run out of “paper width”).
Now, in general hitting the “Enter” key performs a carriage return/line feed; plus text programs have automatic “word wrap” without specifically having to hit Enter.
However, especially in scripting/programming, Mac and Windows treat the end of a line of text differently. Windows standard is to send a CRLF - i.e. carriage return plus line feed. However Mac, being Unix based, uses only a LF. So programs dealing with text sometimes don’t work from one platform to the other without paying specific attention to this detail.