Package-lock.json - requires vs dependencies

Question

In package-lock.json in dependency object, I have both requires and dependencies fields, e.g

  "requires": {
    "@angular-devkit/core": "0.8.5",
    "rxjs": "6.2.2",
    "tree-kill": "1.2.0",
    "webpack-sources": "1.3.0"
  },
  "dependencies": {
    "rxjs": {
      "version": "6.2.2",
      "resolved": "https://registry.npmjs.org/rxjs/-/rxjs-6.2.2.tgz",
      "integrity": "sha512-0MI8+mkKAXZUF9vMrEoPnaoHkfzBPP4IGwUYRJhIRJF6/w3uByO1e91bEHn8zd43RdkTMKiooYKmwz7RH6zfOQ==",
      "dev": true,
      "requires": {
        "tslib": "1.9.3"
      }
    }
  }

What is the difference between these two? Why some dependencies are listed in requires, other in dependencies, and some of them in both of these fields?

Answer 1

After reading the answers above, maybe I can put it more simply:

requires can be shared among all other top levels dependencies, while dependencies are standalone, belonging only to the module requiring them.

i.e.

"@angular-devkit/core": "0.8.5","tree-kill": "1.2.0", and "webpack-sources": "1.3.0" do not belong only to the module. They are in the same level as the module requiring them. By contrast, "rxjs": "6.2.2" exists exclusively due to the module requiring it, and it is used only by that module.