There are the two basic scanning methods interlaced and progressive named by either "i" for interlaced or "p" for progressive, following the number of active lines. An interlaced video format with 1080 active lines would be called 1080i. The frame rate can also be added to the end of the video format name, for example a 1080i format with a 30 Hz frame rate would be called 1080i30.
In interlaced scanning the frame is split into two fields. Of these two fields one field contains the odd lines and the other frame contains the even lines. Displaying the video picture, first all lines from one field are drawn, followed by all the lines from the other field. The two fields are actually from different images taken at different times one after the other. By converting an interlaced image to a progressive one (like 480i to 480p) a sophisticated algorithm has to be implied because the odd lines of the image are spatially shifted from the even lines, due to the interfield motion. This misalignment must be dealt with to create a visually pleasing progressive image.

There are two interlaced video formats currently defined for HDTV: 1035i with 1035 active lines, and 1080i with 1080 active lines. The older 1035i format has been almost entirely replaced now by the 1080i formats.

The HD-SDI standard supports both coax cable and optical fiber interfaces.

In the progressive formats the frame is not split into fields, all lines are generated out of the same original picture and are drawn one after the other sequentially from top to bottom.
There are two progressive video formats currently defined for HDTV: 720p with 720 active lines and 1080p with 1080 active lines.

HD-SDI builds upon the widely used SDI standard used to transport SD digital video. The SD-SDI and HD-SDI standards share the same electrical characteristics and encoding schemes, HD-SDI just uses a higher bit rate to accommodate the higher bandwidth requirements of the uncompressed HD digital video signals.
Because SD-SDI and HD-SDI share the same electrical characteristics, it is possible to build video equipment that can support both standards at the same input.

Format   Scanning Type   Number of Pixels V   Number of Pixels H   Total Number of Pixels per Frame to be displayed 480i 4:3 interlaced 480 640 307,200 480p 4:3 progressive 480 640 307,200 480p 16:9 progressive 483 720 347,760 720p 16:9 progressive 720 1280 921,600 1080i 16:9 interlaced 1080 1920 2,073,600 1080p 16:9 progressive 1080 1920 2,073,600