Explain the statement- CRT screen as a two-dimensional matrix

One can imagine the CRT screen as a two-dimensional matrix which has m rows and n  columns and this is usually referred as raster. Each row of the m rows (or the points on a horizontal line of the screen) is called scan-line. The number of points that can be displayed on the screen (n × m) is defined as the resolution of the screen. The resolution is related to the size of the point that emits light after the contact of the electron beam. Displays can be divided into random and raster scan displays.