To invest is to allocate money in the expectation of some benefit in the future. In finance, the benefits from an investment are called returns.
What is the purpose of investing? We invest money to make more money.
But the first importance of Investment is the security of capital; to protect against loss. Take two investment options with the same risk profile and, assuming nothing illegal or morally dubious is involved, the one with the higher return usually comes out as the winner.