Npm i and npm ci , what difference?

npm install / npm i - installation which can rewrite package.json and package-lock.json

npm ci - clean install which removes node_modules and use package-lock json for installing and do not rewrite them package-lock.json and package.json

npm install

• Installs a package and all its dependencies.
• Dependencies are driven by npm-shrinkwrap.json and package-lock.json (in that order).
• without arguments: installs dependencies of a local module.
• Can install global packages.
• Will install any missing dependencies in node_modules.
• It may write to package.json or package-lock.json.
  • When used with an argument (npm i packagename) it may write to package.json to add or update the dependency.
  • when used without arguments, (npm i) it may write to package-lock.json to lock down the version of some dependencies if they are not already in this file.

npm ci

• Requires at least npm v5.7.1.
• Requires package-lock.json or npm-shrinkwrap.json to be present.
• Throws an error if dependencies from these two files don't match package.json.
• Removes node_modules and install all dependencies at once.
• It never writes to package.json or package-lock.json.