Final answer:
Horizontal resolution is defined as the ability to identify the image dots on each scan line and is a measure of how clearly details can be seen in an image. This is influenced by factors such as wavelength and numerical aperture, and is described by the Rayleigh criterion in terms of diffraction patterns.
Step-by-step explanation:
The ability to resolve the image dots on each scan line defines horizontal resolution. Resolution in imaging technology is a measure of the details that can be seen in an image. It's the smallest distance between two separate points in an image that can be distinguished as distinct entities. Greater magnification improves the ability to see small details, but to enhance the quality of an image, the resolution must be high as well. Components like wavelength and numerical aperture of a lens play crucial roles in achieving a higher-resolution image. In terms of diffraction patterns, the limit for resolution is when the minimum of the pattern for one line is directly over the first minimum or the first maximum for another line, according to the diffraction limit and the Rayleigh criterion.