Differences: Current art uses more defined techniques, and is more likely to employ the elements of art, such as space, form, or texture. Perspective was not used in prehistoric art, making all figures flat and 2 dimensional. Also, prehistoric art was often made with limited materials, while more modern art is often created with a wide variety of supplies, ranging from pencil, to paint, to clay.
Similarities: Both prehistoric and current art are outlets of creativity, along with often being useful, like with artistic maps, and depictions of animals.