Like Matryoshka dolls, the term 'Nested' refers to something that is arranged in a series of boxes, layers, or levels, all contained within one another. Matryoshka dolls are a traditional Russian nesting doll set, consisting of a wooden figure which can be pulled apart to reveal another figure of the same sort inside, and so on. The concept of nesting has been used in many different contexts, from architecture to computer programming.