A collection in a canvas app is used to store data that you can then tap into throughout your application. In this video, he showcases how to store some pre-made comments that users typically will choose from when filling out a form. This will make the app easier and faster to use for the end user. No more typing in the same comment time after time when making records. Now the user can just check the comments they want and they will populate the form for them.
Modifies or creates one or more records in a data source, or merges records outside of a data source.
Use the Patch function to modify records in complex situations, such as when you do updates that require no user interaction or use forms that span multiple screens.
https://docs.microsoft.com/en-us/power-platform/power-fx/reference/function-patch
Power Apps PATCH function is the hardest function to understand. Why? The Patch function is the only function you can use 7 different ways. Yeah, you heard me right. Seven. That’s why I built a no-nonsense cheat sheet that you can use to quickly figure out how the patch function works.
https://www.matthewdevaney.com/7-ways-to-use-the-patch-function-in-power-apps-cheat-sheet/
In Power Apps there are two techniques for making a form: an Edit Form and a Patch form. I favor using Patch forms and I regularly get asked the questions “why should I use a patch form?” and “what are the best practices when creating a patch form?” In this article I will teach you everything I know about creating awesome Power Apps patch forms and guide you through an in-depth tutorial.
https://www.matthewdevaney.com/everything-you-need-to-know-about-power-apps-patch-forms/