To invest is to allocate money with the expectation of a positive benefit/return in the future. In other words, to invest means owning an asset or an item with the goal of generating income from the investment or the appreciation of your investment which is an increase in the value of the asset over a period of time. When you invest it always requires a sacrifice of some present asset that you own today such as time, money, or effort.
In finance, the benefit from investing is when you receive a return on your investment. The return may consist of a gain or a loss realized from the sale of a property or an investment, unrealized capital appreciation (or depreciation), or investment income such as dividends, interest, rental income etc., or a combination of capital gain and income. The return may also include currency gains or losses due to changes in the foreign currency exchange rates.
Investors generally expect higher returns from riskier investments. When a low-risk investment is made, the return is also generally low. Similarly, high risk comes with high returns.
Investors, particularly novices, are often advised to adopt a particular investment strategy and diversify their portfolio. Diversification has the statistical effect of reducing overall risk.