Yep they are the same, but I prefer IEO than ICO because many investors gain profit in IEOs especially they listed in big exchanges. Investing ICO is really risky nowadays many of them are scam so if you really want to invest in ICO you should research carefully the project.
IEO is a good image for investing in projects right now when it is a safe and profitable trend but this hot phase is over, now everyone in the face of IEO, they are always very concerned, projects are not always profitable, sometimes we still lose a lot in the face of the dump status of projects. And with such a change, IEO, ICO and STO are probably reestablishing a balance, no one dares to guarantee which option is better, and investors should probably not continue to look at the trend, they should look at the potential and surrounding elements of the project.