I have several books on my shelves that seek to answer this question: Who is Jesus? Each of them is several hundred pages long.
Jesus is absolutely the most wondrous, extraordinary Person in the history of this world. It is difficult to summarize the dimensions of Who He is and, closely aligned with that, what He has accomplished. His accomplishments infinitely exceed those of any other. So, please accept this post as my best current attempt at a very brief summary of Who He is.