North America TV system is "NTSC"
NTSC is an abbreviation for National Television Standards Committee.
NTSC picture is made up of 525 interlaced lines and is displayed at a rate of 29.97 frames per second.
Now digital TV is using different standard with higher scanning frequency and fram rate to generate higher quality picture.
For example: HDMI 1080P
1080 means 1080 lines and P means progressive (non interlaced)
Now manufacturers claim their products as 4K & 8K TV to simplify confusion to end users.
