Hi monica,
I think most of us don't speak that well Italian so no excuses needed
Anyway here's my input: Most of the so called non-managed switches don't offer any management interface (or very limited). So as a result of that they lack some pretty interesting features:
VLAN creation
Port configuration (auto-negotiation, speed, etc..)
QOS
Trunking
etc..
So it really depends on your needs. If you just look for something that gets your packet from port a to b then an unmanaged switch will do just fine. If your into some more complicated configs than you should look out for the features above.
I'm sure he moderators and senior members can add some usefull info to that
Greetings (ciao)
Stefan