Machines can often work faster, or for longer, or more vigorously than humans.
Consider a postal sorter, a water pump, and a bulldozer.
They are a good substitute for our physical labour.
Humans created machines to help them selves. But machines enslaved humans.
This question makes no sense, but slavery in the 1860’s had no use of machines.
Washing machines help humans by making it easier for humans to wash their clothing. Washing machines have special instructions on how to install and use them. Basically, they make humans' life a lot easier. But, it also uses electricity, which does not help humans. The pollution from the washing machines' electricity makes humans' life harder.
Machines are inanimate. Machines do not eat, sleep, rest, breathe, and they do not have a heart beat. Machines are just objects, inanimate objects for the use of humans.
Plastic molding machines; soldering machines; computer machines; humans; assembly machines; cooling machines; heating machines; electric machines; labeling machines; laser machines; conveyor machines.... etc.
That means that the electrical energy we use is made by machines constructed by humans.
The Modern Era.
Engineers/ humans
Ergonomic designs are engineered with comfort and safety in mind. Ergonomics offers a safe and comfortable use for humans when they use and interact with machines such as computers.
Ergonomics is the science concerned with designing safe and comfortable machines for humans.
Robots are the machines doing the work formerly done by Humans
In the Matrix, the machines use humans as a power source by harvesting their bioelectricity. Additionally, the machines rely on the human subconscious to provide a stable mental environment for the Matrix simulation to function properly. This symbiotic relationship allows the machines to both sustain themselves and maintain control over the human population.