High resolution refers to the spatial resolution size of a satellite image.
In simple terms, the resolution type will determine the clarity of your optical image. The smaller the pixel size, the more “clear” your image will look. High resolution has a smaller size per pixel offered by a satellite provider. The size of a pixel relates to the distance on the ground that is covered by the pixel in the image. For example, with a 50 cm resolution image, each pixel covers 50 cm x 50 cm on the ground.
High resolution can be defined differently among data providers. At SkyWatch, high-resolution data is 50cm-1m per pixel.
Visually, this is what it can look like.