"customer" is used in more general and broader way, but "client" is used more in business and professional environment. For example, if you use the services of a lawyer, he will regard you as a client.
-motown(motown);
2001-3-24(#36720@0)
how about to understand it this way: customer = 顾客,client = 客户 ?
-sw989(Londoner);
2001-3-24(#36721@0)
Londoner, when and which department did you study in Beida? What are you doing in London?
-motown(motown);
2001-3-25(#37046@0)