What is 14,12 and 60 Hive in SharePoint

You'll hear SharePoint people talk about and refer to the "12 Hive" or the "60 Hive" regularly. We don't know what it is and we use it .
The "Hive" concept was coined by Todd Bleeker. So what does it mean?
12 Hive is the location where MOSS 2007 and WSS 3.0 install their files on the file system.  

14 Hive is the location where SP2010  install their files on the file system.  

The same thing applies to 60 Hive which, as you may guess is the location of SPS 2003 and WSS 2.0 files.  

Locations:

  12 Hive  C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\

  14 Hive  C:\Program Files\Common Files\Microsoft Shared\web server extensions\14
  60 Hive  C:\Program Files\Common Files\Microsoft Shared\web server extensions\60