类 (lèi) is a classifier and noun meaning 'category/type', used for broad or formal classifications (e.g., 此类 'this category'). For everyday concrete types, use the classifier 种 (zhǒng) instead (e.g., 一种水果 'a kind of fruit'). As a noun, 类 is more abstract than 种类 (zhǒnglèi, 'varieties, kinds') and less technical than 类别 (lèibié, 'classification').