What is the concept of development? with the reference ?

The concept of development refers to the process of improving the economic, social, and political conditions of a country or region over time. It involves various aspects such as increasing income levels, reducing poverty, improving education and healthcare, promoting gender equality, ensuring environmental sustainability, and enhancing overall well-being.

Development can be understood from different perspectives. One widely recognized framework is the Human Development Index (HDI) developed by the United Nations Development Programme (UNDP). The HDI measures development based on three dimensions: a long and healthy life (measured by life expectancy at birth), access to knowledge (measured by mean years of schooling and expected years of schooling), and a decent standard of living (measured by gross national income per capita).

Another influential concept is Amartya Sen's capability approach, which emphasizes the importance of individuals' freedom to live the lives they value. According to Sen, development should not be solely measured by economic indicators but should also focus on expanding people's capabilities and opportunities to lead fulfilling lives.

References:
- United Nations Development Programme (UNDP): http://hdr.undp.org/en/indicators/137506
- Amartya Sen (1999). Development as Freedom. Oxford University Press.