The act of specializing; making something suitable for a special purpose

The special line of work you have adopted as your career

(biology) the structural adaptation of some body part for a particular function

Specialization is the separation of tasks within a system.

In logic, especially as applied in mathematics, concept A is a special case or specialization of concept B precisely if every instance of A is also an instance of B but not vice versa, or equivalently, if B is a generalization of A. A limiting case is a type of special case which is arrived at by taking some aspect of the concept to the extreme of what is permitted in the general case.

In academic, specialization may be a course of study or major at an academic institution, or may refer to the field in which a specialist practices.

Specialisation, is an important way to generate propositional knowledge, by applying general knowledge, such as the theory of gravity, to specific instances, such as "when I release this apple, it will fall to the floor".

In linguistics, the term specialization, refers to one of the five principles by which grammaticalization can be detected while it is taking place.