A variegated plant is one which has stripes of green skin, which is chlorophyll-rich, and also has areas of white, where there is no chlorophyll to be found.
The precise benefits of this to the plant itself are unproven, but a large number of variegated species are popular as ornamental plants, and houseplants[?].
Spider plants[?] are an example of a variegated species which is widely appreciated as an ornamental plant[?].