Like Fedora vs Redhat? or CentOS vs Redhat.
From what I read, more like Fedora vs Redhat since
openSUSE 15 was released, but SUSE 15 did not yet.
This is important for appliance ISO based on openSUSE like
1.) Security fixes
2.) Application compatibility develop on openSUSE, directly run SUSE
Thanks
Eh? SLE 15 has been out almost as long as Leap 15
put simply the relationship is as follows
openSUSE Tumbleweed (our Rolling release) provides the code which SUSE hardens and polishes to become SUSE Linux Enterprise
That SLE codebase provides the starting point which the openSUSE community then adds additional packages to to become openSUSE Leap (our stable release)
SUSE continually contribute to Tumbleweed as a matter of company policy SUSE Open Source Policy - Redirect in order to continually prepare for the next SUSE Linux Enterprise version
For packages shared between SLE and Leap, openSUSE Leap recieves the same Security fix code as soon as the fixes are released to SLE customers.
Application compatibility should not be a problem as long as you do not build packages on Leap that require packages that are not available on SLE
Shifting to General Chit-Chat as not the appropriate forum. I’m also glad that Richard answered as it saved me from having to explain. 
Moved from Install/Boot/login and open for posting again.
Appreciate your explanation.
Yes, you are right. My bad google search skills.
Recently, start to look into openSUSE. Try to figure out all those puzzles 