This idea suggests increasing the value of the product by making it useful for other things while selling the product at the same price. Customer saves money in the long run instead of buying the tools or parts separately which sums up to a higher price.
One popular example is the swiss knife. It may be sold at a premium price but if you would think about the cost of buying the tools separately, it actually costs more having individual tools.
In the office, you may also see another multi-functional device, that is the multi-purpose printer / fax / scanner. In the earlier times, we had to spend a significant amount to buy each unit separately but now we can save more by having a multi-purpose unit or what we call now as a All-in-One (AIO) Printer.
Another example is the photocopy machine which use to have a sole functionality of photocopying but as time passed it evolved into a multi-functional office equipment. Some photocopiers would now even have functionality of a fax machine, document storage, saving of image into electronic files (pdf or jpeg).