What is the difference between 1080i and 1080p?

1080i refers to a digital video signal of 1080 lines in interlaced video. The 1920 horizontal pixels are usually left out of the name, so the full definition is 1920 x 1080i, a signal with a bit rate of 1.5 Gbps.

1080p refers to a digital video signal of 1080 lines in progressive video. The 1920 horizontal pixels are usually left out of the name, so the full definition is 1920 x 1080p, a signal with a bit rate of 3 Gbps.