The staggered form of ethane has minimum repulsive forces and minimum energy.
The Spatial arrangement of carbon, hydrogen atoms which can be converted into one another by rotation around a C-C single bond is called confirmation or conformer. Staggered confirmation occurs when hydrogen atoms bound to two carbons are as far apart as possible with respect to each other. Since there are less repulsive forces and energy due to the many separations between the electron clouds of C-H bonds, the staggered conformation is more stable than the eclipse conformation.
The staggered form of ethane has minimum repulsive forces, minimum energy, the least torsional strain and maximum stability because the electron cloud of carbon hydrogen bond are maximum apart.