It actually isn't. Just as Huntington's Clash of Civilizations isn't a thing. It's a perception illusion used by people to vilify one side and promote the other.
I'm sure south Asians find it useful to "other" Europeans and Americans to support whatever argument they are making, but its hard referenced in places like Europe and America.
The West as a concept originates in the West. It's derived from the medieval idea of Christendom, ostensibly stripped of its religious significance and instead 'secularised' and pushed on to the rest of the world as a civilizational distinction during colonial times. The use made of it by non-Westerners is a result of this (similarly, the idea of a distinct Islamic civilisation was not invented in The West - despite what this
interesting but flawed recent book argues - and concepts such as
umma and
dar al-Islam originate from the Islamic tradition -
this great article makes the case for Islam as a distinctive world system).
These concepts exist and continue to have relevance because people believe they do, because people identify certain historical legacies, religious heritages, and ethical values with them. Where Huntington went wrong wasn't in identifying that such civilisations exist - it was in downplaying the conflicts that tend to play out
within these civilisations over questions of history, religion, and values (see for example The West 1914-1945) in favour of emphasising conflicts
between them, in assuming clear lines can be drawn between the various civilisations (see the maps in the book), and in emphasising the pull civilisations have on our collective loyalties over alternative draws such as the nation-state, the tribe, the sectarian group, the linguistic group, etc.