Speculation is the purchase of investments where you don't have a clear idea of the value of the investment, and are gambling on the direction of the market price.

Actual investment is usually called "value investing", you purchase assets at a substantial discount to their intrinsic value and wait for the market to recognize that value. True value investing is rarely practiced on Wall Street because Wall Street is mostly about the latest fad and charging fat fees to the uninformed. And when Wall Street firms tout themselves as "Value" they are typically just buying low PE stocks, which isn't actual value investing at all.