Bit rate is a measure of how many bits of data are transmitted per second. Compared to videos with a higher bit rate, the same videos with a lower bit rate would most likely have
a 3D effect.
blocky, pixilated motion.
a larger file size.
a smoother flow of motion.
Less bits are used to encode every video frame, so depending on the compression algorithm this will result in small areas, blocks, getting the same color, i.e., a blocky, pixelated effect.