Email from Microsoft titled "Action Needed – You may lose access to some of your third-party mail and calendar apps" Is this a scam?

I'm 76 and am completely both baffled and concerned by Microsoft's warning.

What is an email client ? How do I know If I use it? what version are they ?? what platform they are installed on ??, what's a platform?and whats a protocol (POP, IMAP, or Exchange Server)?? No idea what any of this means.

Before my PC just worked without me having to go to university to learn how to use it, but now !!

Yep. Exactly what I am talking about. All the gobblygook that I have no idea about. I guess I just wait until sept and see

Mailbox access using a browser is not affected.

iOS mail app may or may not be affected depending on how it is configured.

This article walks you thru fixing iOS mail problem IF you experience it:

https://support.microsoft.com/en-us/office/modern-authentication-methods-now-needed-to-continue-syncing-outlook-email-in-non-microsoft-email-apps-c5d65390-9676-4763-b41f-d7986499a90d#:~:text=Modern%20Authentication%20Methods%20now%20needed%20to%20continue%20syncing,5%20If%20you%20use%20Mozilla%20Thunderbird%3A%20More%20items

If you use Apple Mail:

Apple Mail supports Modern Authentication by default when you setup the account as Outlook.com. If you use Apple Mail and you are seeing password prompts or connection errors, this is most likely happening because your account got configured as basic authentication. To mitigate the issue, remove the account and add it back as Outlook.com:

What that means is that Outlook.com will require Oauth2 ("Modern" Authentication) just like Gmail and Yahoo already do. If your current email client will natively work with either of those, it will work with Outlook.com after the switch-over, though you may need to re-create the account. If your email client does not do Modern Auth, both Gmail and Yahoo will supply (allow you to generate) and require you to use an Application Specific Password instead of your normal password. Outlook.com also has a generator for these passwords. Please see these support articles:

How to get and use app passwords

Sign in to apps with your Apple ID using app-specific passwords

I'm confused.

I access my hotmail accounts both directly online through the outlook website (when using my laptop) AND through the mail app on my iphone.

Will I no longer be able to access my accounts online through the website? Or does this just affect the accounts on my apple mail app?

In both scenarios, can somebody walk me through - step by step - what I'm supposed to do to fix this?