This will install wp-cli in your machine.
Now you no need to worry how to install wp-cli in your machine. If nodejs is intsalled in your machine then all you need to do is
npm install wp-commandline -g
This will install all wp-cli commands in your terminal. The only thing requires is nodejs, php and mysql installed in your machine.
After installing wp-commandline type below command to check whether the wp command is working or not.
wp --info
Here is the list of all wp commands
All the contributors of WP-CLI