Explain the process of composting in brief.

There are two ways of composting:

1. Anaerobic composting — The anaerobic decomposition process occurs without oxygen and produces biogas (methane and carbon dioxide) and compost. This process is less prone to odour and doesn't require aeration. The biogas can be used for energy production and the compost is used as a superior soil conditioner.
2. Aerobic composting — Aerobic decomposition occurs in the presence of oxygen and involves bacteria, fungi, and actinomycetes. It is relatively expensive, produces bad odours, requires aeration, uses additives, and produces greenhouse gases. The micro-organisms in the process grow and break down sugars, starch, and organic acids.