Final answer:
Developed countries have high per capita wealth and standards of living, whereas developing countries face challenges like poor healthcare and education. At least developed countries struggle with very low incomes and industrial development. These terms reflect economic and infrastructural factors, not the value of a country or its people.
Step-by-step explanation:
The key differences between developed, developing, and least developed countries (LDCs) encompass a variety of factors including economic wealth, standards of living, industrialization, and infrastructure. Developed countries like Canada, Japan, and Australia generally have a high level of wealth per capita, advanced infrastructure, and a high standard of living. In contrast, developing countries, which may also be referred to as third-world or emerging markets, grapple with challenges such as rapid population growth, limited healthcare, fewer educational opportunities, inadequate technology, and often, lower per capita GDP. Least developed countries face severe challenges in industrial development, healthcare, and education, and often have very low incomes per capita leading to higher rates of poverty. It's essential to note that these terms are used descriptively and do not indicate a country's worth or its people's value.