What does “publicPath” in Webpack do?

Webpack docs state that output.publicPath is:

The output.path from the view of the JavaScript.

Could you please elaborate on what this actually means?

I use output.path and output.filename to specify where Webpack should output the result, but I’m not sure what to put in output.publicPath and whether it is required.

module.exports = {
  output: {
    path: path.resolve("./examples/dist"),
    filename: "app.js",
    publicPath: "What should I put here?"   
  } 
}