Botany is a natural science concerned with the study of plants. The main branches of botany (also referred to as "plant science") are commonly divided into three groups: core topics, applied topics which study the ways in which plants may be used for economic benefit in horticulture, core topics which associate with agriculture and forestry concerned with the study of the fundamental natural phenomena and processes of plant life, the classification and description of plant diversity, and organismic topics which focus on plant groups such as algae, mosses or flowering plants.