Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasure and are considered to be "fun".

The term recreation appears to have been used in English first in the late 14th century, first in the sense of "refreshment or curing of a sick person", and derived turn from Latin (re: "again", creare: "to create, bring forth, beget").

People spend their time on activities of daily living, work, sleep, social duties and leisure, the latter time being free from prior commitments to physiologic or social needs, a prerequisite of recreation. Leisure has increased with increased longevity and, for many, with decreased hours spent for physical and economic survival, yet others argue that time pressure has increased for modern people, as they are committed to too many tasks. Other factors that account for an increased role of recreation are affluence, population trends, and increased commercialization of recreational offerings. While one perception is that leisure is just "spare time", time not consumed by the necessities of living, another holds that leisure is a force that allows individuals to consider and reflect on the values and realities that are missed in the activities of daily life, thus being an essential element of personal development and civilization. This direction of thought has even been extended to the view that leisure is the purpose of work, and a reward in itself, and "leisure life" reflects the values and character of a nation. Leisure is human right under the Universal Declaration of Human Rights.

Recreation is difficult to separate from the general concept of play, which is usually the term for children's recreational activity. Children may playfully imitate activities that reflect the realities of adult life. It has been proposed that play or recreational activities are outlets of or expression of excess energy, channeling it into socially acceptable activities that fulfill individual as well as societal needs, without need for compulsion, and providing satisfaction and pleasure for the participant. A traditional view holds that work is supported by recreation, recreation being useful to "recharge the battery" so that work performance is improved.

Work, an activity generally performed out of economic necessity and useful for society and organized within the economic framework, however can also be pleasurable and may be self-imposed thus blurring the distinction to recreation. Many activities in entertainment are work for one person and recreation for another. Over time, a recreational activity may become work, and vice versa. Thus, for a musician, playing an instrument may be at one time a profession, and at another a recreation.

Similarly, it may be difficult to separate education from recreation as in the case of recreational mathematics.

Recreation has many health benefits, and, accordingly, Therapeutic Recreation has been developed to take advantage of this effect. The National Council for Therapeutic Recreation Certification (NCTRC) is the nationally recognized credentialing organization for the profession of Therapeutic Recreation. Professionals in the field of Therapeutic Recreation who are certified by the NCTRC are called "Certified Therapeutic Recreation Specialists". The job title "Recreation Therapist" is identified in the U.S. Dept of Labor's Occupation Outlook. Such therapy is applied in rehabilitation, psychiatric facilities for youth and adults, and in the care of the elderly, the disabled, or people with chronic diseases. Recreational physical activity is important to reduce obesity, and the risk of osteoporosis and of cancer, most significantly in men that of colon and prostate, and in women that of the breast; however, not all malignancies are reduced as outdoor recreation has been linked to a higher risk of melanoma. Extreme adventure recreation naturally carries its own hazards.

Recreation is an essential part of human life and finds many different forms which are shaped naturally by individual interests but also by the surrounding social construction. Recreational activities can be communal or solitary, active or passive, outdoors or indoors, healthy or harmful, and useful for society or detrimental. Some recreational activities – such as gambling, recreational drug use, or delinquent activities – may violate societal norms and laws. A list of typical activities could be almost endless.