All new Samsung televisions on sale in the United States as of 2015 are high-definition televisions, including several models that conform to the Ultra HD or 4K standard. However, some smaller Samsung televisions are only HD or 720p models, rather than full HD 1080p displays. Some older Samsung televisions may only display in standard definition, also known as 480p, but these models are no longer in production.
There are several different resolutions considered to be high-definition resolutions that are often referred to by the number of lines of vertical resolution each offers. For example, an HD or 720p resolution display is defined as a display with a resolution of at least 720 horizontal lines. In practice, many displays produced by Samsung and other manufacturers have slightly different line counts, as with many HD displays that actually have 768 lines of horizontal resolution rather than 720. The Ultra HD or 4K standard is technically referred to as 2160p, though the other names for this resolution are much more commonly used.
The "p" portion of a resolution name used to describe Samsung's HD television models refers to a particular display using a progressive scan format, where each horizontal line of a frame is drawn sequentially from the top to the bottom of the screen. This notation differentiates these displays from interlaced televisions using the older 480i or 1080i standard, where alternating lines in each frame are drawn in two passes for each frame. Progressive displays have less flicker and better picture quality than interlaced displays. Much like SD televisions before them, interlaced displays are no longer manufactured by Samsung.