What does Pixels per Inch (PPI) measure?

Pixels per Inch (PPI) measures the density of pixels on a surface. It quantifies how many individual pixels are packed into a linear inch of the display or image area. A higher PPI indicates a greater number of pixels within that inch, leading to finer detail and sharper images. This measurement is crucial for understanding how clear and detailed an image will appear on a screen or when printed.

The other options focus on different aspects of displays or images. Brightness pertains to how well a screen can emit light, while resolution refers to the total number of pixels that make up the entire image rather than the density of those pixels per inch. Additionally, the size of the device’s screen describes the physical dimensions of the display but does not provide information about pixel density or image clarity. Thus, when considering the specific definition of PPI, it directly aligns with the concept of pixel density on a surface.