1. Construction project: refers to a construction unit with legal person status, which is composed of one or several single projects in a general scope, with independent economic accounting and unified administrative management. For example: schools, factories, etc.

2. Single project: refers to a project with independent design documents, which can independently organize construction and independently exert its production capacity or benefit after completion. For example: the school's teaching building, experimental building, library, etc.

3. Unit project: refers to the project that can't exert its production capacity or benefit independently after completion, but has independent design and can organize construction independently. For example: civil engineering, electrical lighting, water supply and drainage, etc.

4. Sub-project: According to the different divisions of the project parts, the types and models of equipment and materials used. Examples: foundation engineering, masonry engineering, concrete and reinforced concrete engineering, decoration engineering, roofing engineering, etc.

5. Sub-projects: divided according to different construction methods, different materials and different specifications. For example, masonry can be divided into brick masonry and rubble masonry, in which brick masonry can be divided into inner wall, outer wall and parapet according to different parts. Sub-projects are the most basic structural elements for calculating labor, materials and capital consumption.