What is Identifiers App IDs -- in Apple -- for?

Getting Started Newbie Questions
#1

Hi Everyone…

Apple has 18 lines…

1 - Certificates

   2 - All

   3 - Pending

   4 - Development

   5 - Production

6 - Identifiers

   7 - App IDs

   8 - Pass Type IDs

   9 - Website Push IDs

  10 - iCloud Containers

  11 - App Groups

  12 - Merchant IDs

13 - Devices

   14 - All

15 - Provisioning Profiles

   16 - All

   17 - Development          [iOS App Development]

   18 - Distribution             [App Store]         [Ad Hoc]

what is item 7 for? – [Identifiers App IDs]

Do I have to have one of those, for each app I make?

Do I have to create it every time, or when I create one of the provisioning profiles, the App IDs will create itself?

#2

Each app needs a unique AppID.  This is your unique com.yourname.yourappname string.   Each app will have an AppID and a Provisioning Profile (or 2 or 3 depending on your specific needs).

You have to create the AppID before you can create the Provisioning Profile.

#3

which program do i need to get enrolled into from the apple developer portal to be able to create the Merchant ID ? 

#4

Each app needs a unique AppID.  This is your unique com.yourname.yourappname string.   Each app will have an AppID and a Provisioning Profile (or 2 or 3 depending on your specific needs).

You have to create the AppID before you can create the Provisioning Profile.

#5

which program do i need to get enrolled into from the apple developer portal to be able to create the Merchant ID ?