to choose which vacuum cleaner to buy we should know some of its characteristics: how much power it will spend, what kind of filtration it uses and what kind of attachments come with it. Read more about vacuum cleaner making process.
Vacuum cleaners were at first made by hand. Today, they are made on the assembly line as most of the modern things. They also have similar principle on which they work but can also differ in details. Read more about how vacuum cleaners works.
Different vacuum cleaners use different technologies to solve same or similar problems. That way we have solutions that have different efficiencies and knowing them and specifications of vacuum cleaners we can choose the one that suits us.