While “digital” commonly refers to electronics in general, the scientific definition of digital is much different. “Digital” in information science refers to the finite, discontinuous phenomenon (e.g., on or off states in a light bulb) as opposed to infinitely varying, continuous analog phenomenon (e.g., the brightness of daylight). It can also refer to representing data in figures as opposed to data represented in pictorial form.
Translation is usually movements like up, down, left, right.
Dilation is when one shape is bigger/smaller than the other, but still congruent.
Reflections are usually done over an axis (x or y), and don't change the degree at which a shape is turned. From looking at the triangles, you can see that one triangle was turned clockwise.