A toilet is a piece of sanitary hardware used for the collection or disposal of human urine and feces. Toilets can be with or without flushing water (flush toilet or dry toilet). They can be set up for a sitting posture or for a squatting posture (squat toilet). Flush toilets are usually connected to a sewer system in urban areas and to septic tanks in isolated areas. Dry toilets are connected to a pit, removable container, composting chamber, or other storage and treatment device. Toilets are commonly made of ceramic (porcelain), concrete, plastic, or wood.
In private homes, the toilet, sink, bath, or shower may be in the same room. Another option is to have one room for body washing (bathroom) and another for the toilet and handwashing sink (toilet room). Public toilets consist of one or more toilets (and commonly urinals) which are available for use by the general public. Portable toilets or chemical toilets may be brought in for large and temporary gatherings.
Historically, sanitation has been a concern from the earliest stages of human settlements. However, many poor households in developing countries use very basic, and often unhygienic toilets - and nearly one billion people have no access to a toilet at all, and are forced to do open defecation. These issues can lead to the spread of diseases transmitted via the fecal-oral route or via water, such as cholera and diarrhea. The United Nations Sustainable Development Goal 6 therefore calls for "access to adequate and equitable sanitation and hygiene for all and end open defecation".