Pianpang
Pianpangs (Chinese: 偏旁; pinyin: piānpáng; lit. 'side side') are components in Chinese character internal structures. A compound character is normally divided into two pianpangs according to their relationship in sounds and meanings. Originally, the left side component of the character was called pian, and the right side pang. Nowadays, it is customary to refer to the left and right, upper and lower, outer and inner parts of compound characters as pianpangs.
Radicals (部首) are indexing components of Chinese characters, and are usually pianpangs representing the meanings of the characters.