A cyclohexane conformation is any of several three-dimensional shapes that a cyclohexane molecule can assume while maintaining the integrity of its chemical bonds.
The internal angles of a flat regular hexagon are 120°, while the preferred angle between successive bonds in a carbon chain is about 109°, the tetrahedral angle. Therefore the cyclohexane ring tends to assume certain non-planar (warped) conformations, which have all angles closer to 109° and therefore a lower strain energy than the flat hexagonal shape. The most important shapes are called chair, half-chair, boat, and twist-boat. The molecule can easily switch between these conformations, and only two of them — chair and twist-boat — can be isolated in pure form.
Cyclohexane conformations have been extensively studied in organic chemistry because they are the classical example of conformational isomerism and have noticeable influence on the physical and chemical properties of cyclohexane.
Read more about Cyclohexane Conformation: Historical Background, General, Chair Conformation, Boat Conformation, Twist-boat Conformation, Half-chair Conformation, Interconversions Between Conformations, Forced Conformations, Cyclohexane Derivatives