Digital images consist of a small dots or pixels. The resolution refers to the number of pixels (dots) per inch (DPI). For example, if an image contains 800-by-600 pixels and has a size of 4-by-3 inches, then the resolution is 800 pixel / 4 inches = 200 DPI. Generally, higher resolution allows you to print or zoom up images to larger sizes without losing quality. Use Windows Explorer to find out the image resolution from the file properties.
Click "Start"; it will open the "Start" menu in the left corner of the screen.
Click "Computer" in the "Start" menu to open Windows Explorer.
Browse your computer using Windows Explorer to the folder that contains an image file.
Right-click on the image file; then select "Properties."
Click on the tab "Details" in the image properties window.
Read the image resolution in dots per inch (DPI), for example, 180 DPI.
An image's size in pixels (2,592-by-1,944 pixels, for example) sometimes also is referred to as the image resolution. Note that the image size (in pixels) is given in the line "Dimensions" in the properties window.