An important appeal of most forms of hedonism is that they are able to give a simple and unified account of their respective fields. The plausibility of the various versions of hedonism is affected by how the nature of pleasure is conceived. Quality theories hold that pleasure is a quality of pleasurable experiences themselves while attitude theories state that pleasure is in some sense external to the experience since it depends on the subject's attitude to the experience. They are traditionally divided into quality theories and attitude theories. Theories of pleasure try to determine what all these pleasurable experiences have in common, what is essential to them. But in its most general sense, it includes all types of positive or pleasant experiences including the enjoyment of sports, seeing a beautiful sunset or engaging in an intellectually satisfying activity. In everyday language, the term 'pleasure' is primarily associated with sensory pleasures like the enjoyment of food or sex.

The term 'happiness' is often used in this tradition to refer to the balance of pleasure over pain. Both pleasure and pain come in degrees and have been thought of as a dimension going from positive degrees through a neutral point to negative degrees. Discussions within hedonism usually focus more on pleasure, but as its negative side, pain is equally implied in these discussions.

Pleasure contrasts with pain or suffering, which are forms of feeling bad. Pleasure plays a central role in all forms of hedonism it refers to experience that feels good and involves the enjoyment of something. In that sense, it has a negative connotation, linked to the egoistic pursuit of short-term gratification by indulging in sensory pleasures without regard for the consequences. These technical definitions of hedonism within philosophy, which are usually seen as respectable schools of thought, have to be distinguished from how the term is used in 'everyday language'. Applied to well-being or what is good for someone, it is the thesis that pleasure and suffering are the only components of well-being. Axiological hedonism, which is sometimes treated as a part of ethical hedonism, is the thesis that only pleasure has intrinsic value.

Normative or ethical hedonism, on the other hand, is not about how humans actually act but how humans should act: people should pursue pleasure and avoid pain. Psychological or motivational hedonism claims that human behavior is determined by desires to increase pleasure and to decrease pain. Hedonism refers to a family of theories, all of which have in common that pleasure plays a central role in them.

Ethical hedonism