Cuba's economy is not very efficient or smooth. After they left the Soviet Union in the 90's, they went into a depression called the "Special Period", where many people were very poor. This country has one of the least free economies. This poverty has led to less education possibilities for citizens and often hunger and malnutriton.
In 2000, their economy got better with their relationship with Venezuela. The Cuban government sent healthcare in return for oil, but living conditions have since not returned to normal. Some people have been able to work at more normal wages, but natural disasters, global economic downturn, and the U.S embargo on goods have really hurt them money-wise.
Cubans have a highly skilled labor force, but they are still unable to make enough personal finance, and their household consumption is only about 55% compared to the rest of the world.
Some of the industries that are beneficial to Cuba are: Sugar, potatoes, citrus, coffee, rice, potatoes, livestock, oil, nickel, pharmaceuticals, steel, cement, cigars.