a line
The term you are looking for is "line." In geometry, a line is a one-dimensional figure that extends infinitely in both directions. It is composed of an infinite number of points and has no endpoints.
A line.
straight line
what is a set of points that is endless in both directions
A line
The term you are describing is a line.
A line Segment.lines go on it both directions for ever.
what is a set of points that is endless in both directions
Naming a line segment involves naming its two endpoints, while naming a line involves any two points on the line. A line segment is a portion of a line, so it has a specific length and is finite, whereas a line extends infinitely in both directions.
A Line ;)
That's the definition of a "line".
Points do not extend, lines do.