What are Radicals
Radicals are a way of classifying Kanji characters. Radicals are found in all kanji dictionaries and taught in Japanese schools. A "radical" is part of the kanji which is found in more than one character. For example, the water-related kanji 汁 [soup; juice], 汚 [dirty], 泡 [bubble], and 泳 [swim] all have the same three-stroke element with the meaning "water" on the left. When you remembered a radical, it's much easier to understand the meaning behind the Kanji.