added intro, centos7 content (#23311)

guide/english/nginx/index.md

@@ -2,19 +2,32 @@
 title: Installation of Nginx in Ubuntu
 ---
 
-## Installation of Nginx in Ubuntu
+## Introduction
 
-Step 1: Update Apt-Get
+- Nginx is a web server which can also be used as a reverse proxy, load balancer and HTTP cache.
+- It is one of the most popular web servers in use and is responsible for hosting some of the largest and highest-traffic sites on the internet. 
+- It is proven to be lighter on resources than httpd/Apache.
+- Nginx is free and open-source software, first released in 2004.
 
-As always, we update and upgrade our package manager.
+## Installation of Nginx on Ubuntu
 
-`apt-get update && apt-get upgrade`
+Update the local package index and install Nginx from default repositories:
 
-Step 2: Install Nginx
+```sh
+$ sudo apt update 
+$ sudo apt install nginx
+$ sudo systemctl status nginx # will check if the server is running as the installation should have started it already
+```
 
-One simple command to install Nginx is all that is needed:
+## Installation of Nginx on CentOS 7
 
-`apt-get -y install nginx`
+Add Nginx repository and install:
+
+```sh
+$ sudo yum install epel-release
+$ sudo yum install nginx
+$ sudo systemctl start nginx # will start the server
+```
 
 #### More Information