The GDP is representing the total production in a year in a particular country of all final goods and services. The GDP per capita on the other side represents the amount of money that the citizens have on average, thus their financial strength. When compared, these two can show totally different pictures, or they may show very similar ones. Some nations do have high GDP and also high GDP per capita, while some have very high GDP , but the GP per capita is average or even low. We can take the UK and India as examples. They have relatively similar GDP's, but when the GDP'c per capita are compared then the UK is light years ahead. One of the biggest reasons for this is the population, as both countries have similar GDP, but the UK has around 20 times smaller population than India, so when the money are redistributed on the amount of population the differences are enormous.
This is the differential weathering.
Weathering is in general the phenomenon of rock disintegration and if different rocks disintegrate at different pace then it is differential.
