Apache web server referred to as simply Apache is a public-domain open source Web server developed by open community of developers. The application is designed to run on a wide variety of operating systems like Unix, FreeBSD, Linux, Mac OS X, OS/2. Visit http://www.apache.org for more details.

In your terminal, issue the following command (by default, httpd is installed). This will install apache if it was not installed.

Step 1:
[root@user Desktop]# yum install httpd

Step 2: To start apache as a service on boot, issue the following command
[root@user Desktop]# chkconfig –levels 255 httpd on