Displacement is the movement of a point relative to a fixed point on a deformable body.

Deformation is the movement of a point relative to another point on a deformable body.

In Lagrangian strain, the original geometry is used as reference geometry.

In Eulerian strain, the original geometry is used as reference geometry.

Positive shear strain results in increase of angle from a right angle.

The normal strain will be positive if the left end of a rod moves more than the right end in the negative x direction.

Strain has nine components in three dimensions.

Strain has six independent components in three dimensions.

At a point in plane strain there are three independent strain components.

At a point in plane strain there are always four zero strain components.