LEDC means that a country is a developing country (as opposed to a developed country). This distinction is connected to the Brandt line which divides the world into developed and developing country, and India is south of this line (=LEDC, less developed country). Some reasons for this is malnutrition, high child mortality and short life expectancy.
It was caused by widespread disconnect with the French monarchy and the poor economic policies of King Louis XXI
Dialect. Dialect is one of the multiple forms of the same language. If a new dialect is created from a language it has the potential to become a language of its own.