How do LAN switches impact on the security of a network?

Dears, LAN switches can increase the security Level of a network with it's own small capabilities : A- Via port security ( selecting which MAC address is allowed to connect to switch) and the action to be done with another device tries to connect to the same port).
B- VLAN : separating the traffic of users ( Voice ,IT dep , sales Dep, and so on ) , this is will help to secure the network since users traffic will be separated according to need and they will communicate to each other via router with Access lists or a Firewall