MP4 is the universal standard. It works on almost all devices (iOS, Android, Windows, Mac).
In some niche archives, "18525" might refer to an ID number for a specific video entry. 🛠️ Technical Review of the Format (.mp4) 18525mp4
Usually uses H.264 or H.265 (HEVC) codecs, which balance high quality with small file sizes. MP4 is the universal standard