Dear student,
The skeletal equation is the equation that represents the reactants and the products involved but is not balanced in terms of stoichiometric coefficient.
For balancing the equation, we start with the skeletal equation only.
Skeletal equations are unbalanced because of the fact that the support structure of the body is our skeleton. In the skeleton, everything is attached. Similarly unbalanced reactions contain only reactants and products so they are the skeleton of the reaction. The number of moles of reactant required and products formed are the attachments to that skeletal reaction and that is the balanced equation.
Regards