Which version is available for download?

At linuxcnc.org/docs/2.7/html/getting-start...etting-linuxcnc.html you can D/L LinuxCNC ( www.linuxcnc.org/linuxcnc-2.7-wheezy.iso ). However, I wonder why the file is named "linuxcnc-2.7" and not "linuxcnc-2.7.4" ??? If I have a file named "linuxcnc-2.7" already on my HDD, I can't tell if it's 2.7.2 or 2.7.3. or 2.7.4. The file that is available for D/L is exactly the same size (in KB) than the file I have downloaded 3 months ago, which makes me suspicious if the file is exactly the same. (However, I'm informed that 2.7.4 wasn't available 3 months ago...).

Does anyone know, what is the key benefit of naming files with different content with same name?
Does anyone know, is the named file certainly version 2.7.4?

The logic might be that any 2.7 version will auto-update to the current latest version through the package manager.

Thanks for answer. I'm afraid my LinuxCNC won't autoupdate, as it's an off-line PC in a garage, just controlling CNC.
So, the question still remains: Is that file 2.7.4. or something else? If it's 2.7.4, I still can't see the reason naming it "2.7" just because some installations autoupdate any 2.7.x versions...