Final answer:
Low-income countries or Less Developed Countries (LDCs) are nations with underdeveloped economies and lower quality of life standards, characterized by poverty, lack of basic services, illiteracy, and lower life expectancy.
Step-by-step explanation:
Countries with less-developed economies and a lower quality of life are known as low-income countries or Less Developed Countries (LDCs). In these countries, most people are poor relative to those in other countries, and they often have limited access to basic amenities like electricity, plumbing, and clean water. Education is not guaranteed, and many citizens are illiterate. Consequently, life expectancy is typically lower than that found in high-income countries.
These nations may also be described using terms from the Cold War era, such as third world, or based on their economic activity, such as peripheral nations. Furthermore, they may suffer from issues such as political instability, corruption, or reliance on core nations for jobs and aid, as is the case with countries like the Democratic Republic of the Congo.