The image resolution ppi refers to which of the following?

• A. The number of colors per pixel
• B. The size of the file in kilobytes
• C. The number of pixels per linear inch in an image
• D. The number of images per inch

Answer: (C)

PPI is about how densely pixel data is packed along a line of the image — it stands for pixels per inch. It tells you how many individual picture elements fit into each inch, which directly affects sharpness and detail. It’s not about how many colors are in a pixel (color depth), not about how big the file is in kilobytes (that depends on resolution plus compression), and not about how many images appear per inch (which isn’t a standard measurement for images at all).

For example, an image printed at 300 PPI will have about 300 pixels along each inch, giving smooth detail, whereas the same image at 150 PPI would have fewer pixels per inch and look softer. If you keep the pixel dimensions the same but print larger, the PPI decreases and sharpness can suffer; if you increase PPI while keeping the same print size, you need more pixels (a larger image) to maintain detail.