Agriculture is the intentional growing of plants for human use.
Farming was punishment for Adam after the Fall, around 4000 B.C., as explained in the Book of Genesis, chapter 3. Civilizations based on agriculture then developed around 3000 B.C., and ever since most human populations have been dependent on agriculture by some 2,000 years ago. .
The cultivation of plants for food, often called gardening or farming, is the most efficient way to produce your own food for the purpose of achieving a self-sufficient lifestyle. There are many different types of plants you can grow for food, each will have its own advantages and disadvantages.
Various amounts of care are involved, from little more than scattering seeds and later checking for a harvest, to permaculture homesteads to large scale industrial agriculture where thousands of acres are devoted to growing one crop (monocrops), using carefully bred and selected seeds (often genetically modified organisms), highly processed man-made chemical fertilizers, and a variety of insecticides, pesticides, and herbicides.
The plants themselves have been selectively bred (hybrid seeds) since the early days of agriculture for many characteristics, including fruit size and yield, disease and pest resistance, drought or wetness tolerance - in fact, any trait that could be imagined to be useful.
While it is immediately obvious that the first purpose for growing domesticated plants is to provide a stable food supply, we also grow plants for fibers to make clothing, to press for oil, or to make into paper. Plants are also grown for real or perceived medicinal properties, like Valerian root or St. John's wort.
By tying a community to the location where its crops are planted, and making the production and storage of surpluses possible, agriculture led to the development of villages and cities, and the need for, invention, and development of civilization itself