What does the term "resolution" mean in Photoshop?

The term "resolution" in Photoshop refers to the amount of detail an image holds, which is typically measured in pixels per inch (PPI). This measurement indicates how many pixels are packed into a linear inch of the image. Higher resolution means more pixels are present in each inch, resulting in a clearer and more detailed image. This is particularly important for print and high-quality digital displays, as a higher resolution can significantly improve the appearance and sharpness of an image.

In contrast, the number of layers in a project refers to the different levels of image manipulation you can achieve. The size of the image in megabytes pertains to the file size rather than the quality or clarity of the image itself. The viewing quality on different screens can vary but doesn't directly dictate the inherent detail captured within the image file like resolution does. Thus, understanding resolution is fundamental to ensuring images are appropriately sized for their intended use, maintaining quality across various applications.