Two purposes:
1. Wireless Client Isolation prevents one Wireless Client connected to an access point to communicate with another one connected to the same access point. (This is a typical requirement on Hot Spots, for instance, or in Corporate Environments with high security needs.)
2. It helps to prevent brute force attacks on clients' user names and passwords
access of one client computer by another client
brute force attacks on clients usernames and passwords
Isolation
To prevent collisions.
This is assuming that there is no outside access to the Ethernet network such as a Internet connection. If there were then firewalls would be needed to prevent a outside intrusion of the network. In addition to physical access security, a wireless network requires authentication and encryption to prevent unauthorized devices from connecting to the wireless network or capturing and decoding the data that is being transferred via a wireless network connection. If the wireless network has outside WAN access then you would also need firewalls as with the Ethernet network.
Ssid broadcast
Disabling the SSID Broadcast.
It is prevent all connected network cards sending at the same time.
You need to disable broadcasting of SSID.
It uses a 128-bit pre-shared hexadecimal key to prevent unauthorized wireless access.
One major disadvantage of wireless networks is that they are hackable from the outside. Security measures are available to prevent or reduce the attacks.
Isolation
use wireless encryption. for example, WPA or WEP (http://en.wikipedia.org/wiki/Wifi#Network_security)
most pepole would says yes as you may want to do personal banking and such and is someone has access to your network you can be prone to someone peeking in to what you do online