OCTOBER 8, 2003 by JOEL SPOLSKY
The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) - Joel on Software
The IBM-PC had something that came to be known as the OEM character set which provided some accented characters for European languages and a bunch of line drawing characters… horizontal bars, vertical bars, horizontal bars with little dingle-dangles dangling off the right side, etc.
If you have a string, in memory, in a file, or in an email message, you have to know what encoding it is in or you cannot interpret it or display it to users correctly.