How to install Magento 2 using composer

The first step would be to create a directory that should be empty.

mkdir magento;
cd magento;

To download Magento with latest version run

composer create-project --repository-url=https://repo.magento.com/ magento/project-community-edition .

To download any specific Magento version

composer create-project --repository-url=https://repo.magento.com/ magento/project-community-edition=2.2.7 . 

This will prompt you for Username and Password, which you can get by creating your account https://account.magento.com/applications/customer/create/

Once you create your account go here https://marketplace.magento.com/customer/accessKeys/ and click on “Create a new access key“.

Then you will get new keys using the public key as the username and private key as the password.

Once you are done with Magento download, install sample data, this step is optional.

php bin/magento sampledata:deploy

Once all the above steps are done you can install Magento like this from terminal

php bin/magento setup:install --db-host=localhost --db-name=your_database_name --db-user=database_username --db-password=database_password --base-url=https://your_domain.com/ --backend-frontname=admin --admin-firstname=Ratnesh --admin-lastname=Kumar --admin-email=ratnesh@domain.com --admin-user=admin --admin-password=admin123 --language="en_US"  --currency="USD"  --timezone="America/Chicago"