What is the difference between png and jpg icons?

PNG: Portable Network Graphics

A PNG image stores a single raster image at any color depth. PNG is a platform-independent format.

Advantages: PNG supports high-level lossless compression. PNG supports alpha channel transparency. PNG supports gamma correction. PNG supports interlacing. PNG is supported by the latest web browsers.

Disadvantages: Older browsers and programs may not support PNG files. As an Internet file format, PNG provides less compression than the lossy compression of JPEG. As an Internet file format, PNG does not provide any support for multiple image files or animation files. The GIF format supports multiple image files and animation files.

JPEG: Joint Photographic Experts Group

JPEG pictures store a single raster image in 24-bit color. JPEG is a platform-independent format that supports the highest level of compression, however, this compression is lossy. Progressive JPEG files support interlacing. You can increase or decrease the level of JPEG file compression. However, file size comes at the expense of image quality. Compression ratios can be as high as 100:1. (The JPEG format can easily compress files at ratios from 10:1 to 20:1 without loss of image quality.) JPEG compression works well with realistic photography. However, for simpler compositions with fewer colors, strong contrast levels, solid borders, or large areas of solid color, JPEG compression does not provide ideal results. Sometimes, the compression ratio is as low as 5:1, causing a severe loss of image integrity. This loss occurs because the JPEG compression scheme compresses similar tones well, but the JPEG compression scheme does not handle strong differences in brightness or handle areas of solid color well.

Advantages: Photographic or realistic works support advanced compression. File size can be controlled with variable compression ratio. Interlacing is supported (for progressive JPEG files). JPEG supports a wide range of Internet standards.

Disadvantages: Lossy compression will reduce the quality of the original image data. When you edit and resave a JPEG file, the quality of the JPEG blends with the original picture data decreases. This decline is cumulative. JPEG is not suitable for simpler images that contain few colors, have large areas of similar colors, or have significant differences in brightness.