One thing that a developing country has that a developed doesn't is high birth rates. Most people in a developed are more focused on their career so they do not want kids. In order to lower the birth rate, the people should focus on their goals and when they are settled down, have kids. Another thing they have more of is death rates, which follows my second statement.
Statistic: China is very populated with births, that is why people have a limited amount of children to have.
Second, a developing country has more death rates than a developed country because they do not have many medical resources so they can not be cured from diseases or a sickness. The way to fix this is to be healthy and get an education, which goes to my third statement.
Statistics: Africa has many deaths because they don not have the health care to keep them living, or enough food.
A developing country has a lower education system than a developed so that is a big reason to what causes all the negative things happening. What these countries need are more school with a good education that will help kids go to a university. Education can help with future inventions and to help scientific things, such as pollution.
Statistic: The United States is known for having good school, that is why many people have great jobs, such as in the medical field or law field.
A negative thing about a developed population is the pollution because of factories and cars. A developing country can learn from that mistake while turning into a developed country by making the technology of businesses and motor vehicles better made.
A developing country needs better health care, this is why they have high death rates because the pollution and diseases. Education can help decrease this problem.
Also, to become a developed country, you are going to want to have a government that is committed to the development of a country. This is biggest thing to do so one you have a committed government, the rest will be easy.
Lastly, low income. If you have low income, it will give u another easy step to turn into a developed country. You just have to commit to wanting to be a developed country because it is a long process.