Here's why:

* Minimizes Torsional Strain: In the chair conformation, all the carbon-carbon bonds are staggered, minimizing torsional strain (the energy associated with eclipsing bonds).

* Minimizes Angle Strain: The chair conformation has bond angles close to the ideal tetrahedral angle (109.5°), minimizing angle strain (the energy associated with bond angles deviating from the ideal).

Other conformations of cyclohexane, like the boat and twist-boat, have higher energies due to increased torsional and/or angle strain.

Key characteristics of the chair conformation:

* Axial and Equatorial Positions: The chair conformation has two types of positions for substituents: axial (pointing straight up or down) and equatorial (pointing out from the ring).

* Ring Flip: The chair conformation can interconvert into another chair conformation through a process called ring flip, where the axial and equatorial positions swap.

* Equatorial Substituents are more stable: Substituents in the equatorial position experience less steric hindrance than those in the axial position, making the conformation with equatorial substituents more stable.