bin is short for binary...consisting of 2 things..binary codes are written into a file which can descrambled encrypted signals..so a bin is a type of file..
A *bin*ary file is the actual program (think of it as a computer's operating system) that your receiver runs on. The bins are continuously being rewritten by the dss community to add features, fix bugs, etc... You can upgrade to a newer bin (which exists as a single file) by downloading it to your receiver, usually thru a serial cable hooked from your computer.
Ariza 700 has a serial port just like most FTA receivers - no usb port. You will need a USB-to-serial converter as well as a serial cable. But the converters are a pain in the a55 to use, so you're better of hooking into a computer with a built-in serial port to save you grief. Also, some receivers use a nullmodem cable and some straight-thru. Make sure you get the correct one or you might have to jtag your reciever.