Compare a dilation to the other transformations: translation, reflection, rotation.

Dilation:  

A dilation is a transformation that produces an image that is the same shape as the original, but is a different size.  

• A dilation that creates a larger image is called an enlargement.

• A dilation that creates a smaller image is called a reduction.

• A dilation stretches or shrinks the original figure.  

it could also be seen with the help of figure attached to the answer.

Translation:

the translation is the shift of the graph either upward or downward, left or right.

it could also be seen from the figure attached to the answer.

Reflection:

A reflection can be thought of as folding or "flipping" an object over the line of reflection.  

• The original object is called the pre-image, and the reflection is called the image.

the figure is attached to the answer.

Rotation:

Rotating shapes means moving them around a fixed point (clockwise or anticlockwise, and by a certain number of degrees). The shape itself stays exactly the same, but its position in the space will change.