The contract as a juridical category interposes a certain classification based on different general criteria, a classification permitting a more equitable characterization of the contract of electric energy delivery as a particular kind of the contract. The necessity of classifications is important for the determination of the juridical nature and regime applicable to the kinds of contracts, which are subordinated to each type. Thus, assigning to a contract the name, that is bilateral or synalagmatic, we shall realize, without being necessary to specify, that the contract will be enforced a certain juridical regime, which is valid for bilateral contracts, without any distinctions.