A position is the index of a character in the text of a buffer. More precisely, a position identifies the place between two characters (or before the first character, or after the last character), so we can speak of the character before or after a given position. However, we often speak of the character “at” a position, meaning the character after that position.
Positions are usually represented as integers starting from 1, but can also be represented as markers—special objects that relocate automatically when text is inserted or deleted so they stay with the surrounding characters. See Markers.
See also the “field” feature (see Fields), which provides functions that are used by many cursur-motion commands.