What this ifconfig output telling me? What is this output of ifconfig telling me? Any explanation of the first in particular would be sweet.

A:~ Linda$ ifconfig

lo0:  flags=8049&lt;UP,LOOPBACK,RUNNING,MULTICAST&gt; mtu 16384
      options=3&lt;RXCSUM,TXCSUM&gt;
      inet6 ::1 prefixlen 128 
      inet 127.0.0.1 netmask 0xff000000 
      inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 
      nd6 options=1&lt;PERFORMNUD&gt;

gif0: flags=8010&lt;POINTOPOINT,MULTICAST&gt; mtu 1280

stf0: flags=0&lt;&gt; mtu 1280

en0:  flags=8822&lt;BROADCAST,SMART,SIMPLEX,MULTICAST&gt; mtu 1500
      options=2b&lt;RXCSUM,TXCSUM,VLAN_HWTAGGING,TSO4&gt;
      ether 00:1e:c2:1d:0c:15 
      media: autoselect
      status: inactive

en1:  flags=8863&lt;UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST&gt; mtu 1500
      ether 00:1e:c2:ba:ce:23 
      inet6 fe80::21e:c2ff:feba:ce23%en1 prefixlen 64 scopeid 0x5 
      inet 192.168.1.2 netmask 0xffffff00 broadcast 192.168.1.255
      nd6 options=1&lt;PERFORMNUD&gt;
      media: autoselect
      status: active

fw0:  flags=8822&lt;BROADCAST,SMART,SIMPLEX,MULTICAST&gt; mtu 4078
      lladdr 00:1f:5b:ff:fe:13:0d:f0 
      media: autoselect &lt;full-duplex&gt;
      status: inactive
Tl;dr
For your Mac &quot;lo0&quot; is almost the same as the &quot;me&quot; is for you in your question!
lo0: is the loopback address of your computer:
wikipedia says:

Implementations of the Internet Protocol Suite include a virtual network interface through which network applications can communicate when executing on the same machine. It is implemented entirely within the operating system's networking software and passes no packets to any network interface controller. Any traffic that a computer program sends to a loopback IP address is simply and immediately passed back up the network software stack as if it had been received from another device.
Unix-like systems usually name this loopback interface lo or lo0.
Various Internet Engineering Task Force (IETF) standards reserve the IPv4 address block 127.0.0.0/8, in CIDR notation and the IPv6 address ::1 for this purpose. The most common IPv4 address used is 127.0.0.1. Commonly these loopback addresses are mapped to the hostnames, localhost or loopback.

en0:
en0 is your first physical network interface.
Usually it's the internal Ethernet nic (Network interface controller).
It's not activated - probably no ethernet cable is connected - and doesn't have an IP-address.
en1
en1 is your second physical network interface.
Usually it's the Wi-fi interface.
It's activated and connected to an access point and has the IP-address 192.168.1.2, the netmask 255.255.255.0 and the broadcast address 192.168.1.255.
fw0:
fw0 is your third physical network interface.
That's your Firewire interface.
It's not activated - probably no Firewire cable is connected - and doesn't have an IP-address.