*gives Zoro-sama a piggy back ride* >_>
Konohamaru: (breathes heavily) Oi! This is what I know sama:
Doton is a resilient elemental style and thus good for using as an overall basic defense. The old man taught me that the earth can either be your friend or foe and if you pay attention it can reveal many things to you. Tobirama and Minato used this advantage, in coordination with their sensor abilities, to determine the the amount of shinobi nearby.
Depending on your concentration, Earth can be present as four types: Sand, Dirt, Rock, or Mud. As a very versatile element, Doton can be used for both offensive purposes. Depending on the skill of the user, one can manipulate the desity of the earth to either become very heavy or become very light as seen when Tsuchikage-dono tried to make Madara's meteor technique lighter to cause less damage to the Allied Forces.
The good thing about earth is you don't need a preexisting source like with water to use its techniques. One can use one's own chakra to do that. And for reference, Doton Jutsu is commonly affiliated with the snake handsign and/or slamming ones palm on the ground.