The "Part 1" in the title indicates that this video is the first in a series, suggesting that there are more workouts to look forward to. The "HD Video Repack" signifies that the video is of high quality, with clear visuals that make it easy to see each move. The term "repack" might imply that the video has been re-released or re-mastered for better quality or accessibility.
The phrase you provided appears to be a specific search query commonly used on file-sharing or "repack" forums to find high-definition digital copies of older fitness videos. abby winters step aerobics girls part 1 hd video repack