as we discussed aboverecursion is the concept of defining method that makes call to itself whenever method calls itselfwe refer to this as recursive call we also consider method to be recursive if it calls another method that ultimately leads to call back to the main benefit of recursive approach to algorithm design is that it allows us to take advantage of the repetitive structure present in many problems by making our algorithm description exploit this repetitive structure in recursive waywe can often avoid complex case analyses and nested loops this approach can lead to more readable algorithm descriptionswhile still being quite efficient in additionrecursion is useful way for defining objects that have repeated similar structural formsuch as in the following examples example modern operating systems define file-system directories (which are also sometimes called "folders"in recursive way namelya file system consists of top-level directoryand the contents of this directory consists of files and other directorieswhich in turn can contain files and other directoriesand so on the base directories in the file system contain only filesbut by using this recursive definitionthe operating system allows for directories to be nested arbitrarily deep (as long as there is enough space in memoryexample much of the syntax in modern programming languages is defined in recursive way for examplewe can define an argument list in java using the following notationargument-listargument argument-listargument in other wordsan argument list consists of either (ian argument or (iian argument list followed by comma and an argument that isan argument list consists of comma-separated list of arguments similarlyarithmetic expressions can be defined recursively in terms of primitives (like variables and constantsand arithmetic expressions example there are many examples of recursion in art and nature one of the most classic examples of recursion used in art is in the russian matryoshka dolls each doll is made of solid wood or is hollow and contains another matryoshka doll inside it linear recursion