A robot designed for a single purpose can perform some specific task well but poorly on some other task especially in a different environment. One recent trend in robotic architectures has been a focus on behavior based or reactive systems. Here, robots with the ability to change their shape could be of great value. When a task or terrain varies, reconfigurable robots can change their shape to get the job done. Robots which can perform such shape shifting are known as Modular reconfigurable robots. They are built up from a number of modules since a module cannot do much by itself but when connected together they can do highly complicated tasks. Modular reconfigurable robots are able to adapt to the operating environment and required functionality by changing shapes. They consist of a set of identical robotic modules that can autonomously and dynamically change the aggregate geometric structure to suit different locomotion, manipulation and sensing tasks. However, creating robots with reconfiguration capabilities is a serious challenge on being met through new designs for reconfigurable systems and new ideas about algorithmic planning and control that confer autonomous reconfigurability.