What is the significance of the similaritiesand differences between william kamkwamba's story and calvin stanley's story

The both story states the hope and perseverance is needed in a situation that you feel that there is no solution. The two stories implies the positive outcome that could inspire people in a lower class or has a disability to move forward no matter what happen and never give up on their dreams because ain't no mountain high enough for a person with a hope as high as the sky.