What kind of damage is caused when a tornado touches the earth?

The damage is primarily wind damage, though damage can also occur from debris impacts.

Weak tornadoes (EF0 and EF1) cause minor to moderate damage. Tree branches are broken with some trees uprooted or snapped. Houses may lose roof tiles or even part of the roof structure. Weakly built structures such as barns may collapse.

Strong tornadoes (EF2 and EF3) cause considerable to severe damage. Most trees are uprooted or snapped. Well built houses will loose their roofs and even same walls. Cars can be lifted up and thrown.

Violent tornadoes (EF4 and EF5) causes devastating to incredible damage. The few trees that remain standing will be stripped of their bark and have only stubs of their larges boughs. Well constructed houses will be leveled to the ground or even wiped clean off their foundations.