What's inside the 21 trial days ArcGIS online ?

[HaiMai]

I want to verify the benefits of the 21 trial days using ArcGIS online. 

As I will have 1 arcgis online acc with 5 named user and access ArcGIS Pro software.  In the case, 5 people want to use arcgis pro software simultaneously. Can It happen on my ArcGIS online ? 

[DanPatterson_Retired]

Are you referring to the 21 day ArcGIS Trial here... with the caveat ....

Trial subscriptions are for non-production use only. Trial subscriptions from multiple individuals and the content they create during the trial cannot be merged into a single ArcGIS Online subscription.

which sort of suggests it doesn't matter since you might as well have the 5 individuals get their own trial, since the content can't be merged in any event.  It is probably because they don't want their product used for short-term projects that may be commercial in nature.  If in doubt, contact your regional office, 

[HaiMai]

I mean 1 ArcGIS online account with 5 named user. The 5 named users use ArcGIS pro simultaneously . Does it work like that ?

[DanPatterson_Retired]

The named user description is here http://pro.arcgis.com/en/pro-app/get-started/named-user-licenses.htm

So concurrency isn't even an issue.

And from there....

The advantage of a Named User license is that a member can use ArcGIS Pro with their assigned license level and extensions on any machine that has ArcGIS Pro installed. With one license, a member can have up to three simultaneous ArcGIS Pro sessions.

[JayantaPoddar]

Yes. 1 ArcGIS Online trial account (organization) will give you the option of creating upto 5 named users. And you will have 5 licenses of ArcGIS Pro that are ready to be assigned to different named user by the administrator of the account. Manage licenses—ArcGIS Online Help | ArcGIS 

[KellyGerrow]

Hai Mai‌

When you start a 21 day trial of ArcGIS Online, you receive 1 trial with 5 named users. These usernames can be assigned to 5 different users who can be assigned individual ArcGIS Pro Licenses. Each user who has a Pro License can be signed in simultaneously. This allows you to experience an organization with multiple users using the software.

If you decide to purchase the software, all the users and content from the single subscription can be migrated to a full subscription. The caveat that Dan_Patterson‌ is referring to is in the case that multiple trial subscriptions are created. In this case, they can't be combined. If you create a single trial with 5 users, 5 users will be able to try the software for 21 days.

Let us know if you have any questions,

-Kelly