Audio Video Interleaved, known by its initials AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology.

HD(High-definition video) video refers to any video system of higher resolution than standard-definition (SD) video, and most commonly involves display resolutions of 1,280×720 pixels (720p) or 1,920×1,080 pixels (1080i/1080p).

1. AVI and HD are lossy formats which sacrifices quality for file size
2. AVI is thought of as a container format with the HD refers to any video system of higher resolution.
3. HD is H264 soft subbed you're not able to see the subtitles while AVI files can contain both audio and video data in a file container

Other Comparison: MOV vs WMV / 3GP vs 3G2 / MP4 vs FLV / MKV vs MP4 / MP4 vs MP3 / 3GP vs MOV / 3GP vs FLV / M2TS vs MP4

Related Post of AVI File formats

Related Post of HD File formats