日字旁, rì zì páng, 表示与太阳或光线有关的字。日部，为汉字索引中的部首之一，康熙字典214个部首中的第七十二个（四划的则为第十二个）。
Next to the word “日”, rì zì páng, indicates a word related to the sun or light. The Japanese part is one of the radicals in the Chinese character index, and the 72nd of the 214 radicals in the Kangxi Dictionary (the four-stroke is the 12th).
对中文而言，日部归于四划部首。日部通常是从上、下、左、右方均可为部字。且无其他部首可用者将部首归为日部。要注意的是在正体中文中，日部与曰部不同，曰部的字型较日部短小；但在简体中文中，两个部首均归于日部。
For Chinese, the Japanese part belongs to the four-stroke radicals. The Japanese part is usually from top, bottom, left, or right. If there are no other radicals available, the radicals are classified as Japanese. It should be noted that in Traditional Chinese, the Japanese part is different from the Japanese part, and the font of the Japanese part is shorter than that of the Japanese part; but in simplified Chinese, both radicals belong to the Japanese part.
偏旁部首的来历与含义
来历：古代人把左右结构的合体字的左方称为“偏”，右方称为“旁”，如今合体字各部位的部件统称为偏旁。
其中以《说文解字》为代表的古代字典，古代字典给汉字分类采取“据形系联”的方法，把具有共同形旁的字归为一部，以共同的形旁作为标目，置于这部分字的首位，因为处在一部之首，所以称为“部首”。
含义：偏旁部首是合体字的构字部件。
扩展资料
“偏旁部首”常常连在一起说，于是有些教师就认为“偏旁”和“部首”是一回事，这是一种误解。偏旁和部首，虽然有某些联系，却是两个不同的概念。
汉字绝大部分是形声字，由形旁和声旁组成，所以，“偏旁”，主要包含形旁和声旁两类。如“语”字，由“言”和“吾”两个偏旁组成；“盆”字由“分”和“皿字底”两个偏旁组成；“问”字由“门字框”和“口”两个偏旁组成。
The origin and meaning of radical radicals
Origin: The ancients called the left side of the left and right structured combined characters “pian” and the right side as “bian”. Nowadays, the parts of the combined characters are collectively called radicals.
Among them, the ancient dictionaries represented by “Shuowen Jiezi”, the ancient dictionaries adopted the method of “connecting according to the form” for the classification of Chinese characters, grouping the characters with common form as one part, and using the common form as the heading. Placed at the head of this part of the word, because it is at the head of a section, it is called “radical”.
Meaning: Radical radicals are the word-building components of ligature characters.
Extended information
“Radical radicals” are often mentioned together, so some teachers think that “radicals” and “radicals” are the same thing. This is a misunderstanding. Radicals and radicals, although there are some connections, are two different concepts.
The vast majority of Chinese characters are pictophonetic characters, which are composed of phonological and phonological characters. Therefore, “radical” mainly includes two types of phonological and phonological characters. For example, the word “language” is composed of two radicals of “yan” and “wu”; the word “pen” is composed of two radicals of “fen” and “dish bottom”; the word “wen” is composed of “door character frame” and ” “Mouth” is composed of two radicals.