What does low-res and high-res mean?
Answer: "Low res" and "high res" are short for "low resolution" and "high resolution." They are used to describe the resolution of a screen or printed image.
There is no technical definition for low res or high res, since resolution standards have continued to evolve for the past few decades. For example, in the mid-1990s, a monitor with a resolution of 640 x 480 pixels was considered high resolution. Today, 640 x 480 is the lowest resolution most monitors support. High resolution is typically considered 1920 x 1080 or higher, which is also referred to as "high definition" or HD.
The same concept holds true for printers. While a resolution of 600 x 300 DPI used to be considered high resolution, many modern printers do not even support that low of a resolution. Today, a high resolution printer may print in 9600 x 4800 DPI, which is several times finer than the previous high resolution standard.
In summary, resolution can be measured in absolute terms, while "low res" and "high res" are relative measurements. Therefore, the terms are best used to compare resolutions rather than define them.