Installing Nginx on Ubuntu is really simple, sudo apt-get install nginx command will do the trick for you. But it does not install the latest stable, instead it will install some latest version of Nginx from Ubuntu repository.
Nginx maintains 2 versions called Mainline and stable. Latest version can be found from here .

Mainline Version :- It has most latest version than stable, but it is on testing stage ( beta version ). This does not recommend for production environment.
Stable Version :- As name implied, it is reliable version, and recommend for production environment.

Purpose of this article is guide how to upgrade or install latest version of Nginx with minimum steps. Let’s look at how to do it.

1) Add stable Nginx repository to the system

#sudo add-apt-repository ppa:nginx/stable

2) Update repositories

#sudo apt-get update

3) Install Nginx

#sudo apt-get install nginx 

4) Verify latest Version

#nginx -v