The vSphere client, home tab is distributed into 4 regions
Inventory(5): It contains all views. Host&Cluster,VM&templates,Storage,Networks & Search. Top most object of vCenter inventory is vCenter server, you can change the name of it but you cannot add or remove it.
Administration(6):This region contains License,vCenter service status, vCenter server settings,User Sessions,Roles,Systemlog
Management(5):Scheduled tasks, Events,Host profiles, customization package,Maps
Solutions and applications(): Gets added depending what application is installed. e.g.VMware data recovery.