Hello, I have already answered this question before, on this, I will talk about this again:

"In a nutshell, this is the initial placement of coins. The bottom line is that there is a company that wants to launch its own crypto-currency, which will be responsible for a certain task. But to launch the development, it is necessary to raise funds, basically this is the sum of the most popular crypto-currencies, such as ether or bitcoin, which the contributors list. In exchange, the company gives its coins, or tokens, which can then be exchanged for other crypto-currencies. That is, it is a kind of crowd-funding and bonds at the same time.
More about it you can see here ICO investment."