Windows – What is a “Magic Packet” for waking a computer?

My wireless adapter (Intel Dual Band Wireless-N 7260) has two settings in Device Manager which I cannot explain.

Wake on Magic PacketWake on Pattern Match

After a bit of research, I found this Microsoft Technet article which defines the feature as follows:

Defines if a network adapter is enabled to wake a computer on the magic packet.

This rather cryptic description is a bit low on details. Can anyone help?

I would prefer that my laptop not be woken up remotely under any circumstances. I’ve disabled Allow this device to wake the computer on the Power Management tab, but these settings appear to be separate. My assumption is that I can set these two settings to Disabled without negative consequences. Is that right?

Solution:

Sam3000’s answer is very nice. I’ll add some technical details.

Wake on Magic Packet causes the network card to awaken the computer when it receives a magic packet. A packet is considered “magic” when it contains FF FF FF FF FF FF (six instances of the largest possible byte value) followed by sixteen instances of the card’s six-byte MAC address. That sequence can appear anywhere within the frame, so the packet can be sent over any higher-level protocol. Usually, UDP is used, but sometimes raw frames with EtherType 0x0842 are used. (Source: Wikipedia.)

Wake on Pattern Match is a superset of the previous. It will cause the card to wake the machine when various things come in, including a magic packet, a NetBIOS name query, a TCP SYN packet (either TCPv4 or TCPv6), etc. Those last ones may require ARP offload to be enabled. (Source: TechNet.)

If you don’t want/need your computer to be woken up from anywhere else, you can disable both of those options.