SQL*Loader supports loading data that is in a Unicode character set.
Unicode is a universal encoded character set that supports storage of information from most languages in a single character set. Unicode provides a unique code value for every character, regardless of the platform, program, or language. There are two different encodings for Unicode, UTF-16 and UTF-8.
In this manual, you will see the terms UTF-16 and UTF16 both used. The term UTF-16 is a general reference to UTF-16 encoding for Unicode. The term UTF16 (no hyphen) is the specific name of the character set and is what you should specify for the CHARACTERSET parameter when you want to use UTF-16 encoding. This also applies to UTF-8 and UTF8.
The UTF-16 Unicode encoding is a fixed-width multibyte encoding in which the character codes 0x0000 through 0x007F have the same meaning as the single-byte ASCII codes 0x00 through 0x7F.
The UTF-8 Unicode encoding is a variable-width multibyte encoding in which the character codes 0x00 through 0x7F have the same meaning as ASCII. A character in UTF-8 can be 1 byte, 2 bytes, or 3 bytes long.
Case study 11, Loading Data in the Unicode Character Set (see "SQL*Loader Case Studies" for information on how to access case studies)
Oracle Database Globalization Support Guide for more information about Unicode encoding