Separation

Separation may refer to:

Separation (United States military), the process by which a service member leaves active duty
Separation (air traffic control), rules to minimise the risk of collision between aircraft in flight
Separation (1967 film), a British feature film written by and starring Jane Arden and directed by Jack Bond
Separation mastering, in music recording

Science

Flow separation, separation of a fluid boundary layer from the surface of a solid body moving relative to the fluid
Separation of concerns, in computer science (and problem-solving in general)
Separation process, in chemistry
Separation axiom, concepts in the area of mathematics called topology
Separated sets, related concept in topology, two sets disjoint from the other's closure
Separation (behavior), the behavior of flocking animals to stand off from their neighbours
Separation (statistics), a problem encountered in fitting models for categorical outcomes

Legal separation, a legal status where married couples may disentangle their finances without divorce
Racial separation, the separation of different racial groups in daily life

Separation of church and state, the idea that religion and government functions should be separate
Political separation (separatism), those seeking to "separate" their group or territory from a larger entity