All investments are assets but not all assets are investments. Assets are “acquired” and owned, while investments are “made” and owned. The intent of an investment is appreciation of value over time. You may own real estate as an asset, but you may also invest in that same real estate with the intent of making a financial gain from it. Typically, one makes investments after conducting meaningful financial investment analysis about the prospects of earning a return in the future, which is not necessarily done when acquiring non-financial assets.
The SEC distinguishes between certain entities owning investments vs. owning assets under some parts of the accredited investor definition. The logic is that requiring ownership of a certain amount of investments instead of assets may better demonstrate that an investor has experience in investing and is therefore more likely to have a level of financial sophistication similar to that of other institutional accredited investors.