Inclusion in education refers to including all students to equal access to equal opportunities of education and learning, and is distinct from educational equality or educational equity. It arose in the context of special education with an individualized education program or 504 plan, and is built on the notion that it is more effective for students with special needs to have the said mixed experience for them to be more successful in social interactions leading to further success in life. The philosophy behind the implementation of the inclusion model does not prioritize, but still provides for the utilization of special classrooms and special schools for the education of students with disabilities. Inclusive education models are brought into force by educational administrators with the intention of moving away from seclusion models of special education to the fullest extent practical, the idea being that it is to the social benefit of general education students and special education students alike, with the more able students serving as peer models and those less able serving as motivation for general education students to learn empathy.

Implementation of these practices varies. Schools most frequently use the inclusion model for select students with mild to moderate special needs. Fully inclusive schools, which are rare, do not separate "general education" and "special education" programs; instead, the school is restructured so that all students learn together.

Inclusive education differs from the 'integration' or 'mainstreaming' model of education, which tended to be a concern. A premium is placed upon full participation by students with disabilities and upon respect for their social, civil, and educational rights. Feeling included is not limited to physical and cognitive disabilities, but also includes the full range of human diversity with respect to ability, language, culture, gender, age and of other forms of human differences. Richard Wilkinson and Kate Pickett wrote, "student performance and behaviour in educational tasks can be profoundly affected by the way we feel, we are seen and judged by others. When we expect to be viewed as inferior, our abilities seem to diminish". This is why the United Nations Sustainable Development Goal 4 recognizes the need for adequate physical infrastructures and the need for safe, inclusive learning environments.

Inclusion has different historical roots/background which may be integration of students with severe disabilities in the US (who may previously been excluded from schools or even lived in institutions) or an inclusion model from Canada and the US (e.g., Syracuse University, New York) which is very popular with inclusion teachers who believe in participatory learning, cooperative learning, and inclusive classrooms.

Inclusive education differs from the early university professor's work (e.g., 1970s, Education Professor Carol Berrigan of Syracuse University, 1985; Douglas Biklen, Dean of School of Education through 2011) in integration and mainstreaming which were taught throughout the world including in international seminars in Italy. Mainstreaming (e.g., the Human Policy Press poster; If you thought the wheel was a good idea, you'll like the ramp) tended to be concerned about "readiness" of all parties for the new coming together of students with significant needs. Thus, integration and mainstreaming principally was concerned about disability and 'special educational needs' (since the children were not in the regular schools) and involved teachers, students, principals, administrators, School Boards, and parents changing and becoming 'ready for' students who needed accommodation or new methods of curriculum and instruction (e.g., required federal IEPs – individualized education program) by the mainstream.

By contrast, inclusion is about the child's right to participate and the school's duty to accept the child returning to the US Supreme Court's Brown vs. the Board of Education decision and the new Individuals with Disabilities Education (Improvement) Act (IDEIA). Inclusion rejects the use of special schools or classrooms, which remain popular among large multi-service providers, to separate students with disabilities from students without disabilities. A premium is placed upon full participation by students with disabilities, in contrast to earlier concept of partial participation in the mainstream, and upon respect for their social, civil, and educational rights. Inclusion gives students with disabilities skills they can use in and out of the classroom.

Although once hailed^{[by whom?]} as a way to increase achievement while decreasing costs, full inclusion does not save money. It is not designed to reduce students' needs, and its first priority may not even be to improve academic outcomes; in most cases, it merely moves the special education professionals (now dual certified for all students in some states) out of "their own special education" classrooms and into a corner of the general classroom or as otherwise designed by the "teacher-in-charge" and "administrator-in-charge". To avoid harm to the academic education of students with disabilities, a full panoply of services and resources is required (of education for itself), including:

Indeed, the students with special needs do receive funds from the federal government, by law originally the Educational for All Handicapped Children Act of 1974 to the present day, Individuals with Disabilities Education Improvement Act, which requires its use in the most integrated setting.