Different types of dependencies in a Node.js application explained

In the cycle of creating or using node js projects every developer once in a while encounters the phrases like: npm i package_namenpm i package_name --save-devnpm i package_name -g Now there are other flags as well like: P.S. i is shorthand for install npm i package_name --save-optionalnpm i package_name --no-save What are the meaning of these flags?