Save guides, add subjects and pick up where you left off with your BBC account. Straight lines can be drawn in any direction. Horizontal lines go left and right. Vertical lines go up and down.

A horizontal line (a row) in a video frame ... The scan lines are the vertical resolution of the system; for example, an NTSC TV signal uses 525 lines, 480 of which contain image data ("active ...

For example, a resolution of 400 lines refreshed 60 times ... the beginning of the next line. Same as "horizontal sync frequency" in TV. Contrast with vertical scan frequency.

Save guides, add subjects and pick up where you left off with your BBC account. Straight lines can be drawn in any direction. Horizontal lines go left and right. Vertical lines go up and down.