Hedonism refers to a family of theories, all of which have in common that pleasure plays a central role in them. Psychological or motivational hedonism claims that human behavior is determined by desires to increase pleasure and to decrease pain. 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. Axiological hedonism, which is sometimes treated as a part of ethical hedonism, is the thesis that only pleasure has intrinsic value. 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. 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". 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.
Pleasure
Pleasure plays a central role in all forms of hedonism; it refers to experience that feels good and involves the enjoyment of something. Pleasure contrasts with pain or suffering, which are forms of feeling bad. Discussions within hedonism usually focus more on pleasure, but as its negative side, pain is equally implied in these discussions. 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. The term "happiness" is often used in this tradition to refer to the balance of pleasure over pain.
In everyday language, the term "pleasure" is primarily associated with sensory pleasures like the enjoyment of food or sex. 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. Theories of pleasure try to determine what all these pleasurable experiences have in common, what is essential to them.