You can find the full list of EEs available here. If you dig down into each of those, it might tell you the differences.
My guess is v24 refers to Red Hat Ansible Automation platform versions (2.4 vs 2.5). I don’t know what changes in the execution environments besides the ansible-core versions and other dependencies.
The execution environments are independent of the AAP version when using them, they are marked with the AAP version they were released though. You can check the EEs life cycle table in the official docs here for the details
As samccann mentioned, If in doubt when using Red Hat products with subscriptions, it’s always best to reach support through the Red Hat customer portal, the forum is a volunteer and community effort, not an authoritative source for Red Hat Ansible Automation Platform troubleshooting.
That said, this is the best place to help you use Ansible, as in writing playbooks, roles, collections and modules.