Using yarn instead of npm

npm is the default package manager, but Facebook, in collaboration with Exponent, Google, and Tilde, has since developed a better alternative, called yarn, which we will use instead.

yarn (https://yarnpkg.com/en/) uses the same https://www.npmjs.com/ registry as the npm CLI. Since they both just install packages inside node_modules directories and write to package.json, you can use npm and yarn interchangeably. The differences are in their methods for resolving and downloading dependencies.