What are the differences between first and third world problems?

The differences between the first world countries and third world countries, including some relevant aspects like the mentality of the society, the economy and the politics.
When people talk about the poorest countries of the world, they often refer to them with the general term Third World, and they think everybody knows what they are talking about. But when you ask them if there is a Third World, what about a Second or a First World, you almost always get an evasive answer. Other people even try to use the terms as a ranking scheme for the state of development of countries, with the First world on top, followed by the Second world and so on, that's perfect - nonsense. 
To close the gap of information you will find here explanations of the terms. 
The use of the terms First, the Second, and the Third World is a rough, and it's safe to say, outdated model of the geopolitical world from the time of the cold war.There is no official definition of the first, second, and the third world. Below OWNO's explanation of the terms. 
Four WorldsAfter World War II the world split into two large geopolitical blocs and spheres of influence with contrary views on government and the politically correct society: 1 - The bloc of democratic-industrial countries within the American influence sphere, the "First World".2 - The Eastern bloc of the communist-socialist states, the "Second World". 3 - The remaining three-quarters of the world's population, states not aligned with either bloc were regarded as the "Third World."4 - The term "Fourth World", coined in the early 1970s by Shuswap Chief George Manuel, refers to widely unknown nations (cultural entities) of indigenous peoples, "First Nations" living within or across national state boundaries.