"Bespoke" is a term derived in the 18th century when a cloth was considered to "be spoken for", when it was selected by a customer at a Savile Row tailoring establishment. At that time any suit which was made after the customer selected the cloth was called a "bespoke" suit. However, today more than one process of tailoring is offered. What was "truly bespoke" in essence is one of the offerings, besides made-to-measure and ready to wear, and some adaptations of all these types of tailoring.
Bespoke tailoring is the high end suit making technique. It involves the maximum human touch and provides the highest level of individual customization.
The essence of the "bespoke" suit is in the process that is followed to make it by the Savile Row tailors or other good tailors in Europe and around the world. The process involves a detailed measurement of the individual and then a pattern which is specially made for each customer. Then a first fitting takes place which is genuinely a raw assembling of the various parts of the suit. At this stage, often the raw seams are opened and reattached with pins during the fitting, so as to "drape" the suit jacket properly on the individual. Then a second fitting is done, incorporating the changes made in the first and only then the suit would be finished. Minor alterations would also be done once the suit is finished, in case needed.