-Biggest difference is regulations, accesability. Anyone can join an ICO, almost no one can join an IPO. You need big cash for an IPO, you can join most ICOs with 10$ or less.

-In an IPO there is mutual cooperation, the devs are obliged to the investor to show results and investors are oblidged to the devs to show they are helping it build/grow in any way they can. From business strategy's, connections, marketing, improvements.

-In an ICO there is none of that and the whole relation is founded on trust, trust that devs will deliver as they say and trust towards investors that they back the project up financially. Devs are not oblidged by law or regulation to deliver results and could make a ''run for the money''. Leaving investors heartbroken.

-With an IPO the investor is oblidged to hold investments atleast 6 months after stock release.
-With an ICO the investor can choose to step out any point aslong as its listed on an exchange or he should arrange a deal with someone outside of the exchanges.
-IPOs are most beneficial towards the early birds and hardly profit the average joe that can buy into them only once they are fully released on the stock market.
-ICOs are beneficial towards anyone who knows what they're doing or took some lucky guesses.