1394 Net Adapter is for Firewire (IEEE1394, I-Link) port, which is used to import digital videos. You can also use it for IPod and external HDD.
Dell Wireless 1450 Dual Band WLAN mini PCI card. It is for wireless network. That is to say, you can access Internet wirelessly when you close to a WiFi hotspot (you need to pay) or your next doors leave their Wireless access point open.
Dual band: there are diiferent frequency bands for WiFi connection, a, b and g. Dual bands are b and g, g faster than b.