About

A line of text is a list of character until a end of line character is reached.

Management

Line Separator

A line separator is known as an end of line. See Characters - Newline - End of Line ( EOL ) - Line Separators - Line Break

Adjacent

An adjacent relationship between line means that the line are sequentially next to each other.

There is a direct relation.

Line 1 and 2 are adjacent wheras line 1 and 3 are not.

Length

See UI - Length of a Line (of Text) (Measure of Characters per Line, CPL)