tax和taxation有什么关系？

当做名词的时候，

tax: an amount of money that you have to pay to the government so that it can pay for public services such as road and schools.

taxation:
1、Taxation is the amount of money that people have to pay in taxes.
2、Taxation is the system by which a government takes money from people and spends it on things such as education, health, and defence.

从词义来说，tax和taxation在说税金的时候，指的差不多东西，但是taxation更强调税金的款值
但taxation本身也指税收这个社会制度

而且tax作动词就是征税的意思，taxation是纯名词

英语中有很多单词，自己既是名词也是动词，但是依然可以动词名词化
tion是名词后缀之一，比较常见