You create the color purple by mixing equal parts red and blue. Red and blue are primary colors. The other primary color is yellow. Purple is a secondary color. A secondary color is created by mixing two primary colors.
The color purple is associated with royalty, mystery, wisdom and magic. (see second link)
The other secondary colors are green, which is mixed from yellow and blue, and orange, mixed from yellow and red. You can make the secondary colors darker or lighter. By adding white, to make it lighter, you can create lavender. You can create other shades of purple by adding more of either of the primary colors blue or red.