What does multi-site WordPress application mean?

Question

I have a WordPress application. I have been added as administrator in that blog application. I haven't access on the application server. After login to admin section, I am not able to see any post or page? But, on the homepage (blogs.xyz.com), I can see that there are multiple links like

• blogs.xyz.com/hospitality
• blogs.xyz.com/healthcare
• blogs.xyz.com/insurance

I am very new in WordPress and don't know about this behavior of WordPress.

• How can I get access on all these sites?
• Has Multiple been installed for all these sites or a single WordPress is enough for this?
• Why should we do this?

Answer 1

You would need to contact the super administrator if you want more capabilities however here's a summary.

Super Admin – somebody with access to the site network administration features and all other features.

Source http://codex.wordpress.org/Roles_and_Capabilities

The capabilities of the site administrator role are reduced in a WordPress Network. Site admins cannot install new themes or plugins and cannot edit the profiles of users on their site. Only the Network Admin (Super Admin) has the ability to perform these tasks in a WordPress network.

Your site is part of a multisite network using the same domain and your site address is a sub domain.

http://codex.wordpress.org/Multisite_Network_Administration