Core 3 Release 1 vs Core 2

[Terry Linhardt <linhardt swbell net>]

Can someone in the know explain how a new "Core" differs from a prior
Core number.  Does Core 3 imply that there will be new features bundled
into the product that just do not exist in Core 2, even if fully
updated?

By it's nature, is Core 3, Test 1, for instance, "less stable" than core
2 ?   Would Core 2, for instance, be considered a "release" while Core
3, Test XX be considered a "pre-release" or beta?

Elementary questions, I guess. But, I want to understand how to regard,
for instance, Core Release 2 vs Core Release 3 Test 1.

Thanks...Terry