What is the purpose of a file with the .png extension?

A file with the .png extension is an image in the PNG (Portable Network Graphics) format. It is a raster graphics format that supports lossless compression and transparency (alpha channel).

The purpose of a .png file is to store and display high-quality images, especially when transparency or clarity of details is important.

In the context of Node.js, such files are often used for web resources (icons, images on websites) and can be processed using various libraries for uploading, transforming, or optimizing images.

Example of using the sharp package to process PNG in Node.js:

const sharp = require('sharp');

sharp('input.png')
  .resize(200, 200)
  .toFile('output.png')
  .then(() => console.log('Image has been changed'))
  .catch(err => console.error(err));

Thus, .png is a universal format for high-quality images with support for transparency.