What exactly do I get when I purchase an older version of Mac OS X? I recently acquired an older iMac 5,1 with 3 GB RAM, currently running Mac OS X 10.6.8, and from what I can gather online it is able to run "Mac OS X 10.7.5 Lion". I found that it is available for purchase on Apple's website for $20, but I do not consider $20 worth fixing up this old machine.

However, if this purchase was tied to my Apple ID or something and worked on multiple machines, that would be nice since it would mean I could fix up any other vintage Mac computers with this version of Mac OS X by signing into my Apple ID?

So, if I purchased an old version of Mac OS X, such as 10.7.5 Lion, what do I get exactly? An upgrade for just one machine? A license tied to my Apple ID? An ISO file for installing Lion? Do they ship a physical disc? Also, am I able to do a clean install or is it just for upgrading?
In the past you could buy USB physical media for Lion but the item you linked to is a redemption code delivered by email. You then have the ability to associate that purchase with one Apple ID of your choosing so you can download and install.

Apple offers pre-sales support if you need more questions about this (or any product) and the end user license allows you to run Lion redeemed from the store on all of the machines you own and control but likely no virtualization or time-sharing allowed. Full details are online if you want to read through things before ordering or calling pre-sales support.


https://www.apple.com/legal/sla/