The population made up of Taiwan is not as complicated as in the United States.  It's simply divided into three groups, which are the descendants of early immigrants (approximately before the end of World War II), the descendants of late immigrants (approximately after the end of World War II), and native inhabitants (see Picture C2 ~ C6 ↓).  All these three groups can be further subdivided into subgroups.  Most of the immigrants came from the southern coastal areas of China no matter which groups they belonged to. 

The differences between the early immigrants and the late immigrants were in the following:

1.  The early immigrants had experienced the period of time as a colony of Japan.

2.  The early immigrants' main language was Taiwanese.

3.  The late immigrants' could only speak Mandarin.

After the World War II, Japan lost and China (Republic of China) regained possession of lost territory, Taiwan, in 1945.  New immigrants (late immigrants) started to come to Taiwan.  They soon made up all the officials in the government.  Unlike the well-arranged colonial government of Japan, the government of ROC back then was inefficient, corrupt, incompetent, and rotten.  They discriminated those who were not "late immigrants."  They banned the use of Taiwanese in school.  In other words, they tried to convert the offspring of those early immigrants to not to speak Taiwanese.  They became richer and richer as the early immigrants became poorer and poorer.  Therefore, serious conflicts between the early immigrants and the late immigrants happened frequently in early decades.

However, it does not really have that much of differences between the descendants of early immigrants and those of late immigrants nowadays (see Picture C1 ←).  Most of us are bilingual; we use Mandarin and Taiwanese as our main languages.  In addition, some people can't even be separated into one of these "old-fashioned" categories because they are mixture of these two kinds of immigrants.

Picture C1 My High School Classmates (家盆 攝)
 (Some of them are the descendants of early immigrants, some of late immigrants, and some are both.  We can not tell them apart from appearances.)

A third group of population make up in Taiwan is the native inhabitants.  They are contributed only a small portion of the population.  In general, their skin color is a little bit darker than other new comers.  They are more concentrated in mountain areas of the eastern part of Taiwan (see Picture C7 ~ C10 ↓).   Furthermore, they are subdivided into different groups.  Each group has their own culture, beliefs, special customs, and spoken languages.  However, their traditional lifestyle has changed rapidly.  Their culture is disappearing. 

Picture C7 Eastern Taiwan (光復書局 43)

Picture C8 Eastern Taiwan (施添福[2] 66)