You might be new to crypto world but definitely not to Internet searches nor for youtube tutorials. Instead of asking such a question about IEO why not you could make your own research either in Google or in this forum. I suspect you must be asking this just for counting your posts.

I like to request all other forum members not to feed for the people who are finding themselves to lazy to go for their own searching for what they actually looking for before posting like this type of topics. Only due to this type of people some good boards are being marked as "spammer's heaven: by mods. I believe already we might be having hundreds of topics explaining what is IEO and how to safeguard ourselves while investing into IEOs.