What type of transformation is described as changing location without altering size or orientation?

The transformation defined as changing location without altering size or orientation is referred to as a translation. In a translation, every point of a shape or figure moves the same distance in the same direction, resulting in the figure maintaining its size and orientation throughout the movement.

This kind of transformation is significant in geometry as it helps in understanding how shapes can be manipulated in a two-dimensional plane without changing their fundamental properties. For example, if a triangle is translated to a new position on the coordinate plane, it will retain its side lengths and angles despite being in a different location.

The other types of transformations mentioned—reflection, rotation, and dilation—serve different purposes. Reflection flips a shape over a line, creating a mirror image; rotation turns a shape around a fixed point; and dilation involves resizing a shape, either enlarging or reducing it, which affects its proportions and dimensions. Thus, in the context of the question, translation is the only transformation that solely changes the position without any alteration to size or orientation.