What about contracts that can be made orally (i.e. not in writing)?
Some types of contract will be legally valid and binding although only made orally. (These types are too numerous to list). In these cases, all that is needed is for the parties to show their intention to be legally bound.
These types of contract can alternatively be made in writing and signed. In that case the contract terms can be in electronic form, with electronic signatures included in the document: opting to put the contract in written form is then simply the parties chosen means of demonstrating that they intend to be legally bound.