I am interested to know the differences in functionality between a public and organizational AGOL account. Is it necessary to have an Organizational account in order to host Feature services published from ArcGIS Desktop?
You could check the following link.
Nothing specific about services. I assume that the Public Account cannot host feature services as there is not associated with credits (unlike the Organizational account).
If you are using it for development use only (see detail below), you may want to look into signing up for a free developer account instead of a personal account.
ArcGIS for Developers | ArcGIS for Developers
Number of free credits are limited, but it does give you many of the Org features, plus a few more. Additional credits can be added at a monthly rate if needed.
Access our awesome hosted services (hosted data storage, analysis, geocoding, directions, maps, etc) provided through the planYou can develop and test apps using our developer tools and APIs. If you're going to generate revenue or are using the app for government or business purposes, you'll have to upgrade to a paid subscription when you're ready to make your application available.You can also use this plan to build apps for public, non-revenue generating, non-government, non-commercial use.You can also sell your apps to anyone to use with their paid ArcGIS Online subscriptionIf you are using 3rd Party development tools, you must include attribution acknowledging that your app is using online services provided by Esri
BTW - personally, I recommend not tying this account to you Org email.....it can get confusing when trying to log on to various sites, especially on certain browsers. More email/passwords to remember, but cleaner when needing to look at different accounts. (in my opinion).
According to ESRI support it is not possible to publish Feature Services from ArcGIS Desktop to a Public Account. It is possible to upload shape files that are available as layers (so long as not greater than 1000 features..nb total storage limit of 2GB).
Also, features imported to a Public Account are only available to a single web map. See:
Features vs. feature services in ArcGIS Online | ArcGIS Blog
Useful design pointers:
Who can make this ESRI'S reply simple and easy to understand ?
There are some differences in the functionality between Public accounts and Organization accounts as you have described above. Here are some links to the FAQ and documentation that outline some of these differences:
What is an ArcGIS Account and how is it different from an Esri Account?
How much storage space do i get?
Prerequisites to publish hosted web layers
Retrieving data ...