Texture Section of the 3D Materials Ribbon

Use the buttons in the Texture section of the Materials ribbon to specify the layout of image files applied to object surfaces.

Note: Keep in mind that texture can also be applied to the inside of three-dimensional shapes, and to the back side of two-dimensional shapes.

The shape of the primitive (or other object) will determine how you apply mapping:

X, Y, and Z determines the axis along which you want the texture mapping to be applied to the object. Refer to the axis legend to determine which axis is which; for more information, refer to The X, Y, and Z Axis Legend in the 3D Viewport.
Automatic Mapping is used by default when you apply an image.
Planar Mapping works best for flat surfaces, such as the polygon and cube primitives;
Cylindrical Mapping works best for cylinders and tubes, pipes, and cones; and
Spherical Mapping works best for sphere primitives.