The other open port looks a bit like a telephone port, but has more contacts in it.
I think the HP has such a port as well. It's labeled "Ethernet".

Those are the network ports, they use the TCP/IP protocol, or Ethernet, they are what make it possible for computers to be connected into networks.

Yes you have a USB hub, I assume you have several USB devices conne cted through it.

A network switcch looks like the following Netgear - FS108 - 8-Port 10/100 Network Switch. A Local Area Network might look like theis Expanding Network by Using Network Switch , this example connects to the internet via an ADSL Modem. The examples on this page include a Router, which is like a switch only "smart", in that it contains an embedded Operating system (usually Linux), Switches are basically passive devices, whereas Routers have the ability to act as miniature Domain Name Servers and DHCP (Dynamic Host Configuration Protocol) servers. DHCP servers make it possible for you to simply "plug and play" on your network, as the computer asks the DHCP server to assign it an IP address, and you don't have to set up the net work's IP addresses manually. Additionally Routers act as border guards between different networks, translating one set of network addresses into something another network can understand and work with, while Switches, being passive, work merely to shunt packets of data around a single network.

Networks are basically computers that communicate across groups of IP addresses, a set of IP addresses on interconnected computers, that read 192.168.1.x, where x is one of a set of numbers from 0 to 255, are on the same network., 192.168.2.x is a different network, as is 10.0.0.x or 10.0.1.x etc.