Minor patch? Major patch? How to tell?

[RyuPower]

many times with software versions
X.YZ

X changes=major update (big update, adds many new things and many bug fix)
y changes=minor update (medium update, add small things and fixes bugs
z change=bug fixes (small update, fixes bugs)

is what i think

[Eekiki]

many times with software versions
X.YZ

X changes=major update (big update, adds many new things and many bug fix)
y changes=minor update (medium update, add small things and fixes bugs
z change=bug fixes (small update, fixes bugs)

is what i think

The goofy release cycles of web browsers has screwed with people's conceptions of point releases. Back in the day it was

(X.Ya)

X = new version...usually this meant having to purchase a new copy of the software (think of the difference between Windows XP and Windows Vista)
Y = point release...major update, new features (see MacOS X)
a = hotfix...bug fixes and security updates (generally denoted by a letter instead of a number, since the possibility exists for more than 10 point releases)

So what SE is doing falls somewhat in line with this. 3.0 will be the first expansion pack, which we will have to purchase. Everything else will be 2.1, 2.2, etc.

[Dazusu]

many times with software versions
X.YZ

X changes=major update (big update, adds many new things and many bug fix)
y changes=minor update (medium update, add small things and fixes bugs
z change=bug fixes (small update, fixes bugs)

is what i think

What?

major.minor.build.revision is the general scheme used, at least its how we do it at work, some companies prefer to use the date as a version stamp