Ember difference in naming specified in package.json V/s index.js

Question

For an Ember addon/engine project, what is the difference in the name specified in package.json V/S the one specified in index.js

package.json
{
  "name": "parent-my-ui",
  "version": "1.0.0"
}

index.js
module.exports = EngineAddon.extend({
    name: 'my-ui',
});

Is it fine to have different names for both? What is the practical usage of both of them (specifically in a parent/child engine kind of setup) ?