Each type of mining is adopted for different geological conditions and done so in order to minimize costs and maximize profits for the company. Shallow deposits tend to be mined by surface methods - strip mines or open-pit mines. Deeper mineral deposits tend to be mined by underground mines.
They are similar in that they are trying to extract non-renewable mineral and coal resources by the most economically efficient way they can.
They differ in the risk to workers. Surface methods tend to pose less health and safety risks compared to underground mines which usually have more risks.