Why use a maven repository manager

Question

I've been using maven since a year for managing my projects' dependencies, but I recently came to know that there is a concept of Maven Repository Manager.
I would like to ask What is a Maven Repository Manager and what is the purpose of using maven repository manager.

Answer 1

A "Maven Repository Manager" is basically a server that stores copies of all of your libraries so that they can be downloaded when a project is built. When you use Maven, you are using a repository manager already called "Maven Central." See here: https://maven.apache.org/repository-management.html

When you are working with a large project or corporation, they may host an alternative to Maven Central, like Sonatype Nexus. There are two reasons why they do.

First, a big corporation might have libraries that are intended only for internal use that are used across a large number of projects. For example, if you worked at Amazon, you might have libraries for completing credit card transactions. That shouldn't necessarily be shared with the rest of the world, so you don't want to put it in Central; you need to put it someplace private.

Second, it reduces bandwidth. If every developer at Amazon only used Maven Central, then that would be lots of network traffic. A repository acts as a "proxy" to Central. It searches internally for a library, and then if it doesn't find it, it downloads it from Central and then saves it for the next time someone asks for it.