What is the common resolution for graphics used on the web?

The common resolution for graphics used on the web is 72 ppi (pixels per inch). This resolution is historically significant because it was widely adopted due to the resolution of monitors at the time when digital imaging began to gain traction. The pixels on most displays render at approximately this density, making images at this resolution appear optimal for online viewing without unnecessary file size increases.

Using 72 ppi allows for faster loading of web pages since images are less complex and their file sizes are generally smaller compared to those at higher resolutions. While modern displays are becoming increasingly high-resolution, the standard of 72 ppi persists in many web applications for compatibility and performance reasons. Other resolutions like 150 ppi, 300 ppi, and 96 ppi are more suited for print and specific applications where higher detail is required, thus making them less ideal for everyday web graphics.