This question is in reference to Atlassian Documentation: JIRA applications overview
So, I've read the documentation about being able to update JIRA Software from within JIRA itself, and I understand that to upgrade JIRA Core I have to download the installer.
What I'd like more clearly explained is what do I and what don't I get if I upgrade JIRA Software and not Core, and the reverse, can I upgrade JIRA Core without upgrading JIRA Software?
Just a bit clearer on differences is all I ask for.