What is the significance of the reverse domain name for java package structure

Question

Why do we use reverse domain name like com.something. or org.something. structure for java packages? I understand this brings in some sort of uniqueness, but why do we need this uniqueness?

question from:https://stackoverflow.com/questions/2475168/what-is-the-significance-of-the-reverse-domain-name-for-java-package-structure

Answer 1

Globally unique package names avoid naming collisions between libraries from different sources. Rather than creating a new central database of global names, the domain name registry is used. From the JLS:

The suggested convention for generating unique package names is merely a way to piggyback a package naming convention on top of an existing, widely known unique name registry instead of having to create a separate registry for package names.