We think the MP4 and MPEG4 are the same due to their similar word and some parameters,but the fact is, MP4 and MPEG4 are not the same at all.
MP4 is a container used to store video, audio and subtitles or images. So technically, it's short for MPEG-4 Part 14. And the MPEG4 is just the major standard of video image compression. The important thing is the MPEG4 contains 3 video encoder, MPEG-1, MPEG-2, and MPEG-4 for video, but no MPEG-3 here, instead, it has MPEG Audio Layer 3.
And since the differences, we can change those two formats when we need, thus why we can use some mp4 to mpeg freeware to convert video to MPEG.So the next time when somebody asking whether the is mp4 and mpeg4 the same, you will know how to say.Good Luck.