Numerous definitions of education have been suggested by theorists belonging to diverse fields. Many agree that education is a purposeful activity directed at achieving certain aims, especially the transmission of knowledge. But they often include other aims as well, such as fostering skills and character traits. However, there are deep disagreements about the exact nature of education besides these general characteristics. According to some conceptions, it is primarily a process that occurs during events like schooling, teaching, and learning. Others understand it not as a process but as the achievement or product brought about by this process. On this view, education is what educated persons have, i.e. the mental states and dispositions that are characteristic of them. However, the term may also refer to the academic study of the methods and processes taking place during teaching and learning, as well as the social institutions involved in these processes.
Some researchers, like R. S. Peters, have proposed precise definitions by spelling out the necessary and sufficient conditions of education, for example: (1) it is concerned with the transmission of knowledge and understanding; (2) this transmission is worthwhile and (3) done in a morally appropriate manner in tune with the student's interests. This and similar attempts are often successful at characterizing the most paradigmatic forms of education but have received numerous criticisms nonetheless, usually in the form of specific counterexamples for which the proposed criteria fail. These difficulties have led various theorists to develop less precise conceptions based on family resemblance. This means that all the different forms of education are similar to each other even though they need not share an essential set of features characteristic of all of them. This view can also be combined with the idea that the meaning of the term "education" is context-dependent and may thus vary depending on the situation in which it is used. Having a clear idea of what the term means is important for various issues: it is needed to identify and coherently talk about it as well as to determine how to achieve and measure it.
There is disagreement in the academic literature on whether education is an evaluative concept. So-called thick definitions affirm this, for example, by holding that an improvement of the learner is a necessary requirement of education. However, different thick definitions may still disagree among themselves on what constitutes such an improvement. Thin definitions, on the other hand, try to give a value-neutral account of education. A closely related distinction is that between descriptive and prescriptive conceptions. Descriptive conceptions aim to describe how the term is actually used by regular speakers while prescriptive conceptions try to express what good education is or how it should be done.
Many thick and prescriptive conceptions base their account on the aims of education, i.e. regarding the goals that the activity of education tries to achieve. These aims are sometimes categorized into epistemic goods, like knowledge and understanding, skills, like rationality and critical thinking, and character traits, like kindness and honesty. Some theorists focus on one overarching purpose of education and see the more specific aims as means to this end. This can take the form of socialization, in which accumulated knowledge is transmitted from one generation to the next with the goal of helping the student function as a regular citizen in society. More person-centered definitions focus on the well-being of the student instead: education is to help them lead a good life or the life they wish to lead. Various researchers emphasize critical thinking as an aim in order to distinguish education from indoctrination. This is motivated by the idea that mere indoctrination is only interested in instilling beliefs in the student without concern for their evidential status. Education, on the other hand, should also foster the rational ability to critically reflect on those beliefs and question them. However, some theorists contend that certain forms of indoctrination may be necessary in the early stages of education until the child's mind is sufficiently developed.
Education can be characterized from the teacher's or the student's perspective. Teacher-centered definitions focus on the perspective and role of the teacher, for example, in the form of transmitting knowledge and skills while doing so in a morally appropriate manner. Student-centered definitions, on the other hand, outline education based on the student's experience in the learning process, for example, based on how education transforms and enriches their subsequent experience. However, conceptualizations taking both perspectives into account are also possible. This can take the form of describing the process as the shared experience of a common world that involves discovery as well as posing and solving problems.