we can download magento2 in 3 ways.
1) Direct Download
2) Using COMPOSER
3) Using GIT

Before install magento2 on localhost, we need to check is our server
fulfill the Magento2 system requirement or not. Check the below link.

http://devdocs.magento.com/guides/v2.1/install-gde/system-requirements-tech.html

<strong>Using Window/Linux operating System without composer:-</strong>

Step1: Download magento from magento website using below url.

https://magento.com/tech-resources/download

Put that zip folder to your root path (/var/www/html/) and unzip it.

Step2: Rename the folder name as per your project name and give the 777 permission of that folder.

Step3: create a db on your local machine.

Step4: Run that url on your local browser
http://localhost/YOURPOJETCNAME/setup/ (On step 2 folder name)

Step5: Now follow your browser steps and install magento2 latest version on your local machine.

NOTE:- If you are installing first time Magento2 on your localhost. I suggest don’t
use composer due to chceck magento2 system requirment either compatible or not.