Differences between ICO, IEO, and IDO

In an ICO, issuers handle all of the responsibilities for managing transactions and operations, while in an IEO, a centralized exchange host handles everything.

 In fact, the only difference between IEO and IDO is the platform that hosts the fundraising process. 

Typically, organizations can directly swap tokens with individual investors and traders in both IEO and IDO.

 However, because an IDO is self-organized and decentralized, you do not have to pay an exchange fee as you do in IEO.

 Community members rather than exchanges vet projects and coins. The IDO is, in fact, a hybrid of an ICO and an IEO, with 

the sole difference being that a centralized exchange (CEX) is replaced with a decentralized one (DEX).