VLAN handling on Cisco Switches

These notes appear on a scratch paper found on my desktop. They seem useful and I'll try to see that they are ok.
In order to add a vlan:

vlan database
vlan <id> name <name>
exit
show vlan name <name>

In order to add a port to an existing vlan:

conf t
interf <interface>
switchport mode access
switchport access vlan <vlan>

In order to delete a vlan:

vlan database
no vlan <vlan>
exit

I cannot understand the meaning of the following:

set vtp mode transparent
show vtp domain