Conformation: The shapes that a molecule can adopt due to rotation around one or more single bonds. Eclipsed. Staggered.
Representation of Conformation of Alkanes
Newman Projections: This is one of the ways to represent conformations of alkanes. It visually represents the bonding of atoms from front to back. A Dot represents the first carbon atom (the one that is nearer). The further carbon atom is a circle. Lines show the hydrogen atoms bonded to each carbon atoms. This representation clearly indicates the dihedral angles.
Sawhorse Projections: This represents the conformations of alkanes in form of a straight line. The first carbon is at the lower end of the line on the left side. And the second carbon is at the upper end of the diagram. Here, the lines attached to carbon atoms show hydrogen atoms.