Mac apps vs desktop apps

Your Mac comes with a number of apps installed by default; they are either shown in your dock and more are in your Applications folder.

Apps available at the app store may be additional ones available from Apple or third party vendors.

There is no "one or the other" - it depends on which apps you want to use and/or do what you need them to do.

I always try out the ones already installed by default first; if they lack a feature or whatever, I then go search for more in the app store.

The mac app store has apps that will run on Macs (computers). The other app store on iDevices is exactly for only those devices - iphones, ipads, etc.

Some developers make apps for only iPads for instance; others make them for all the iDevices. And some make their apps compatible with computers and make the same apps separately for iDevices. Computers run on macOS and iDevices on iOS - different operating systems = different requirements for apps. You can't install an app available at the app store on a computer and vice versa. You need to look at the compatibility requirements on all apps.

I have a mix of apps from the App Store and from other places. For example I have an Office 365 subscription with Microsoft, so I've downloaded and installed Microsoft Office from their website. On the other hand my favorite app to listen to radio stations is myTuner Radio Pro which you can find in the App Store :)

As mentioned previously, look for the software you'll need and go from there :)