That is called a cursor.
If you are talking about a one-space long horizontal line that 'blinks' when the rest of the screen is all black, that is for a DOS command. Prior to the original Windows, all computers ran from the DOS prompt. For example, to copy a file you needed to go to the DOS prompt and type in a command line and the entire file name. The command line uses switches, e.g. the forward slash \ and spaces between pieces of the command. The way it was written had to be exact. Today, you will find the DOS command prompt under "Run" and type in cmd into the box. Google for "command prompt syntax" for lists of common commands.
It is called a horizontal line!
The horizontal line is called the horizontal axis
the line that goes from left to right, not up and down. it is actually called the x-axis
a horizontal line.
Horizontal is left to right across like this line:__________________
In the co-ordinate plane The horizontal number line is the 'x-axis'. The vertical number line is the y-axis. They intersect at the 'origin' ; coordinate (0,0) In the 3-dimensional system there is a third number line going from front to back , this is the z-axis. All three axes intersect at the origin , and have the the coordinates ( x,y,z) = (0,0,0)
The horizontal row is called period.
Vertical is the Y-Axis Horizontal is the X-Axis -------------------------------------------------------------------------------------------------------- Vertical is up to down Horizontal is left to right
abscissa is horizontal and ordinate is vertical one
On the Cartesian plane the horizontal number line is the x axis.
A horizontal line is a line that goes across (left to right or right to left).
It is called the "ordinate" axis.