Orca is a screen reader. As the name implies, a screen reader produces audio output when interacting with menus, windows, and applications in Linux, or as you type text in an application.
Apt-get or yum can be used to install Orca.
[root@server1 ~]# apt-get install gnome-orca
[root@server1 ~]# yum install gnome-orca
After Orca is installed, Orca needs to be started. In this example, typing Orca in search produces an option to start the screen reader.