Question on Video Resolution on Pioneer Plasma


I would like some to better understand video resolution.

I own a 3 years Pioneer PDP-5071HD Television. I was looking up something the other day and the manual gives the # of pixels as 1365 x 768.

I know that this is not 1080 resolutions but this is more than 720. Also the TV will state that is displaying 1080i and 1080p signals at times.

Can someone please explain this to me? Also we love the picture but would it be worth moving onto one of the newer Panasonic Plasmas?

Thanks
golfercurt
We have 2 Panasonic plasmas, a 720 50" and a 42" 1080. Both have great pictures and I can't tell a significant difference. Possibly if I played Blue Ray on both I could but on Direct no.
Thank you for the detailed response. I am going to try an experiment in a couple of days. I have the Pioneer TV with an Oppo BDP-83 downstairs and a new Panasonic 42" G25

I am going to bring the Panasonic downstairs one day and try a side by side comparison to determine if I can see a difference.
And don't forget a good HDMI cable. Monoprice has one that is great value; I use Wireworld Silver and Van den Hul, I'm a dealer for the latter. I also replaced the power cord with a small Oyaide on both [ you have to find one with a smaller plug.] I also use power conditioners.