Investment risk not only includes the risk that no increase in value will be generated by the asset, but also the risk that the asset itself will decrease in value to some extent (or even become worth nothing at all). Risk and return will vary over time.
All assets have a degree of risk, as well as a degree of likelihood that they will generate an increase in value. Assets include things like bonds, commodities, stocks, financial derivatives such as futures or options, land, or businesses. Each different asset has a different degree of risk as well as a different likelihood of generating an increase in value. The decisions involved in investing are largely about comparing estimated risks and returns for different assets as accurately and realistically as possible.
Every business is involved in investment as it uses the assets it owns or controls to generate an increase in value in terms of either cash flow or increasing asset values. These assets used by a business can be either physical or not.
Real estate is a common type of asset used as an investment, although many people have considerable misunderstandings about how this works. Residential real estate is the most common category of real estate investment and is considered less risky than commercial real estate.
Other assets used for investment can include such things as stocks, shares, jewelry, bonds, art, commodities, metals (such as gold or silver), and many other things. As with any type of investment, there will always be risks associated with each of these asset categories as well as the potential gains in value from owning them for a particular period of time.