npm for the rest of Bootcamp to build more complex apps that rely on 3rd-party packages.npm init initialises the NPM project, and the -y flag sets our answers to yes for all of the setup questions.package.json specifies all configuration for our Node project managed by NPM. It operates similarly to the .git folder in our Git repos that configures everything Git-related for each repo.package.json file in VSCode.npm install.import syntax to import Node modules. Before Node version 12 the default syntax was require, and much documentation online still references the old require syntax.import and require, but we will use import where we can for consistency. To use import with Node.js we will need to add the "type": "module" key-value pair to package.json.export default from the imported module. There are no named exports with require syntax.npm install, our NPM project will now list the installed package as a "dependency", i.e. a package that our app depends on to run properly. NPM will also have installed all of our package's dependencies, and their dependencies ad infinitum. NPM packages almost always depend on other NPM packages, because nobody builds apps from scratch. For example, here is the dependency graph for the eslint NPM package that we have been using since Coding Basics.npm install.npm install, NPM adds a new key in package.json called "dependencies" if it doesn't exist already. NPM installs the most recent version of the package as a dependency, and lists the package name and version number in the "dependencies" object in package.json so that other copies of this repo can also retrieve the same package version. If we need a specific package version that is not the latest, we can specify it when we run npm install.npm install, NPM creates a file called package-lock.json (if it doesn't exist already) that records version numbers of all dependencies of the target package (and the dependencies of those packages, ad infinitum), so that if we reproduced this repo on another computer, we would use the same dependency versions. package-lock.json is managed by NPM and we should never have to manually edit package-lock.json ourselves.npm install, NPM creates a folder called node_modules (if it doesn't exist already) with the package we installed and all of the packages it depends on. You may notice that there are many more folders in node_modules than packages we installed explicitly, because node_modules contains a folder for every dependency of every dependency. Similar to package-lock.json, node_modules is managed by NPM and we should never need to manually modify code within node_modules.package.json and package-lock.json to Git so that other computers and team members can access the same versions we are using, eliminating bugs due to version mismatches.node_modules to Git, because node_modules can get quite large and everything in node_modules can be installed on an Internet-connected machine by running npm install in the project root folder where package.json is. Committing a large, redundant set of files like node_modules will unnecessarily slow down Git operations, especially pushing and pulling from GitHub..gitignore, and that this file often has a line that says node_modules. This file tells Git which files or folders to ignore when detecting changes. In this case, we have set .gitignore to ignore the node_modules folder so that we never commit node_modules to the repo. Read more about .gitignore here.package.json called "devDependencies". dev or development dependencies are dependencies used purely for development purposes, which developers do not want to be included in the application package deployed to end users. The primary reason for this is to reduce the size of the app for faster load times.-D flag to npm install commands.cows package.index.js file in the cows package we installed in node_modules. Are you able to understand the code?