The Orionids originate from Halley's Comet -- officially named 1P/Halley. The comet is named after astronomer Edmund Halley. The comet has a 75- to 76-year orbit around the Sun. It last passed through the inner solar system in 1986.
So, every October, the Earth crosses the orbit of Halley’s Comet. The meteors are debris from Halley's Comet.
We see the meteors in the night sky as they enter the atmosphere of Earth and vaporize when they hit the molecules in our air.
The meteors themselves seem to come out of the constellation Orion (Orion the Hunter), which is designated the Orionid's radiant. Specifically, the radiant seems to come from the Club of Orion, and will be north of the star Betelgeuse.
You'll be able to see the Orionids from October 16th to October 27th.
For October 2012, the peak of the meteor shower, is expected to produce around 25 meteors per hour; however, up to 70 meteors per hour could result as seen in the past.
Off-peak amounts should be around 15 per hour.
The YouTube video, above, is entitled "Orionid Meteor Shower 2011-10 HD Time Lapsed" (http://www.youtube.com/watch?v=xRe6b1UN_ec)
Its caption states, "Location:Lake Towada Aomori & Akita; Camera:Canon EOS 5DmarkⅡ,7D,Nikon 14-24 F2.8,Tokina 11-16 F2.8".
The image is from a past year's Orionid Meteor Shower: "460 × 221 - Orionid Meteor Shower, Orion the Hunter, constellation Orion, meteor shower. Look up".
Page two concludes.