What does this mean?

Note, the native resolution is 720p, but it also supports 1080i via downconversion. Got this tidbit from this deal that Philips is offering on a TV:

Philips Store has 42 in Pixel Plus LCD Flat HDTV (1080i/720p, 1366x768) with integrated tuner for $1250 - 10% coupon PHILIPSHIDEF-2007 = $1125 with free shipping and no tax for most. Cheapest on PriceGrabber is $1500+. Thanks superior

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Note, the native resolution is 720p, but it also supports 1080i via downconversion. This unit comes with 1-year warranty.

Specs:

Brightness: 500 cd/m²
Response time (typical): 8 ms
Panel resolution: 1366 x 768p
Dynamic screen contrast: 1650:1:
Inputs:
1x HDMI
2x Component
1x Composite
Other models which the coupon works on:

37" Pixel Plus LCD Flat HDTV $1098
50" Pixel Plus DLP Projection HDTV $1152. Thanks Tinman [Discuss]
60" Pixel Plus DLP Projection HDTV $1350 . Thanks Tinman [Discuss]
42" Pixel Plus 3 Clear LCD Flat HDTV $1500
42" Pixel Plus 3 Clear LCD Flat HDTV $1800
50" Pixel Plus 3 HD Plasma Flat HDTV $1890