What is the difference between 720p and 1080i?

Top get started let me explain what p and i means, the p stands for pixel, the i stands for interlaced. So when you see 720p that means it has 720 individual pixels, and when you see 1080i it is actually 540p interlaced with 540p to make 1080i. So the better picture is subjective, the 1080i will refresh faster but the 720p will be crisper better picture, in my eyes. The best picture will always be the P as in Pixels.

Actually the "p" stands for progressive. The difference between interlaced and progressive scans are that when you are watching TV on an old TV set, you'll notice that the picture seems to have horizontal lines in it. What is happening is that you are actually watching an interlaced scan image. In layman's terms, you are seeing only half of the picture (every other line at a time) every 1/60 of a second. On a set with progressive scan capability, the TV is displaying all lines at the same time, which gives the appearance of a clearer picture. The higher the number (1080 for example), the more "lines of resolution" you are seeing, meaning that the picture will have a lot more fine detail in it. On a set with 1080i capability, you are less likely to see actual horizontal lines in it because they're much more tightly packed together than an old TV set, which has the maximum capability of approximately 500 lines interlaced.