Final answer:
A pixel is the term for one square of color that forms photos in Photoshop and is used as a measurement for height and width.
Step-by-step explanation:
The term for one square of color that, with multiple squares of color, forms photos in Photoshop and may be used as a measurement for height and width, is Pixel. A pixel is the smallest unit of a digital image. It represents a single point of color and is used to create images in programs like Photoshop.