Favicon question - manifest.json / browserconfig.xml?

How do favicons work in meteor exactly?

Context:

(1) Go to https://www.favicon-generator.org/ and generate icons.
(2) It gives me a number of files + says, add this in your <head> components.

<link rel="apple-touch-icon" sizes="57x57" href="/apple-icon-57x57.png">
<link rel="apple-touch-icon" sizes="60x60" href="/apple-icon-60x60.png">
<link rel="apple-touch-icon" sizes="72x72" href="/apple-icon-72x72.png">
<link rel="apple-touch-icon" sizes="76x76" href="/apple-icon-76x76.png">
<link rel="apple-touch-icon" sizes="114x114" href="/apple-icon-114x114.png">
<link rel="apple-touch-icon" sizes="120x120" href="/apple-icon-120x120.png">
<link rel="apple-touch-icon" sizes="144x144" href="/apple-icon-144x144.png">
<link rel="apple-touch-icon" sizes="152x152" href="/apple-icon-152x152.png">
<link rel="apple-touch-icon" sizes="180x180" href="/apple-icon-180x180.png">
<link rel="icon" type="image/png" sizes="192x192"  href="/android-icon-192x192.png">
<link rel="icon" type="image/png" sizes="32x32" href="/favicon-32x32.png">
<link rel="icon" type="image/png" sizes="96x96" href="/favicon-96x96.png">
<link rel="icon" type="image/png" sizes="16x16" href="/favicon-16x16.png">
<link rel="manifest" href="/manifest.json">
<meta name="msapplication-TileColor" content="#ffffff">
<meta name="msapplication-TileImage" content="/ms-icon-144x144.png">
<meta name="theme-color" content="#ffffff">

(3) I add this code in my client/main.html, and put all the various ico files in my public folder.

Question: it seems to work, as i can now see the favicon in my browser next to the name of the app.

Q1. How do I know all the other are working?
Q2. What is the point of the public/manifest.json and public/browserconfig.xml - do i put these into the same public folder in my app?

Any pointers would be appreciated. It seems to work, but i have no idea what it is actually doing.