Gunjan has just passed her senior secondary examination from a CBSE affiliated school. She wanted to start her own business but was unable to decide about the nature of the business. One day during the morning walk her grandfather fell down in the park and was injured. She observed that her grandfather often forgets to take his medicines. She thought that the same problem may be faced by other old people. She thought to develop an instrument for old people that could be fitted with an electronic device connected to the mobile phones of the members of their family which could indicate the location of the old people when they go outside their homes. This device could be kept in their pockets. She also thought to fit a timer in the instrument that could remind the old persons about the time of taking their medicines. Identify and state the meaning of the concept described in the above para that helped Gunjan in structuring her idea for solving the problem.