Why do some devices use batteries and other devices use a wall outlet for power?

The explanation regarding why do  some devices use batteries and other devices use a wall outlet for power is described below;

The following information should be considered:

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Some devices are used while moving around from place to place ... like in the car, on a bicycle, running, or walking the dog. If not for batteries, those devices would need very long extension cords.

it is because acrylic blanket have acrylic textile fiber

explanation:

its is better than wool blanket