Performance
NPM: While NPM has improved significantly over the years, especially with the introduction of NPM 7 and 8, it was traditionally slower than Yarn due to the way it handled network requests and caching.
Yarn: Yarn was initially faster because of its parallel downloading of packages and more efficient caching mechanisms. Yarn introduced features like offline caching and deterministic installs, which sped up installations.

Security
NPM: NPM has a security feature called npm audit that scans dependencies for vulnerabilities and provides fixes or workarounds.
Yarn: Yarn also includes similar security checks with yarn audit, and it is generally considered secure. Yarn’s lock file yarn.lock
is slightly more strict, which can make your builds more predictable.

Offline Mode
NPM: npm has no offline mode,
Yarn: Offline mode for seamless installs.

Yarn Disadvantages
Takes more space in hard disk
Problem with installing "native module"
Yarn doesn't work with Node.js versions older than 5, as it was developed by Facebook.

Initialize a project with npm:

npm init

yarn init

Run test for current packages:

npm test

yarn test

install dependencies:

npm install

yarn

Install packages:

npm install [package name]

yard add [package name]

Uninstall packages:

npm uninstall [package name]

yarn remove [package name]

Update manager:

npm update

yarn upgrade