As obvious from its name,it is an investment programme where you get high returns(higher than your local bank accounts offer).High yield is attatched with high RISK also.These are usually online programmes which claim to process your invested amount in forex,offshore trading,commodities,etc and give away a portion of their profit as a high interest to its investors.Some of the HYIP programmes even work out the invested amount in other HYIP programmes and share the profit with you.
Receiving and sending payments online are done through e-currencies.It is same as real money,except that is can be traded online only.You have to create an online account(for free!) and then fund it through your bank account or credit card.Then using this amount in your e-currency account you can do all the money transactions online.
Mostly e-currency used by 95% hyips
Once you have your account on libertureserve you may fund it.Obviously you need to exchange real money into e-money.One of the safest you can use is
GOLDEXCHANGE.EU