Most written Asian languages are based on ideographic symbols, rather than the alphabet, for example, Japanese, Korean, Simplified Chinese, and Traditional Chinese. They have thousands of characters beyond the limit of one-byte representation, i.e. 256 characters. (Hangeul in Korean characters is not an ideographic system but has more than 256 characters in it.) If we use two bytes, namely, 16 bits, we can present 65,536 (256x256) kinds of characters. So we need two bytes for each character to create coded character sets for these languages.
Processing these languages on a computer, then, requires some way to represent thousands of characters, using two bytes to represent one character.
DBCS input methods are different from those used with alphabet-based languages. It makes keyboard operation and/or input handling more complex compared to the SBCS world.
Currently, two single-byte positions are used to print and display one double-byte character in monospaced font environment such as full screen sessions.
The complexity of the characters used in the ideographic languages also requires higher resolution of displays. The minimum resolution for the DBCS character font is 16 x 16. A typical resolution for business quality personal computer displays (or printers) accommodating Kanji/Chinese characters is 24 x 24 or more dots per character.