Vacuum cleaners typically have long cords attached that plug into an electrical outlet, providing the device with power when you need to use it. The problem with corded vacuums is that the long cords can get easily tangled as you're vacuuming your home. Plus, sometimes the cords are not long enough, so you must unplug it and find another plug closer to the area you're trying to clean. Cordless vacuums solve these problems.
A cordless vacuum does the same job as a corded vacuum — sucking up dirt and debris on your floors and other surfaces, such as furniture, and storing it in a bag or compartment. The difference is that a cordless vacuum does not have to be plugged into an electrical outlet to receive power.
Cordless vacuum cleaners typically get their power from a battery source. These batteries are rechargeable, so that when the vacuum is not in use, it is plugged in to a charger. The charger, in turn, is plugged into an electrical outlet in your home. Thus, your vacuum is indirectly getting its charge from your home's power supply, just like a corded vacuum. But, unlike corded vacuums, a cordless one holds the charge for later use.
A cordless vacuum's advantages are clear, with convenience being the main one. You can take a cordless vacuum anywhere without having to untangle wires from under couch or table legs. Putting away a cordless vacuum is also easier, because you don't have to collect the long cord and wrap it around the cord storage clips. Also, they are more versatile, and can be used to vacuum the inside of your car easily, without the need to run a long extension cord out from your garage.
Cordless vacuums have a limited power supply. When the battery charge is used up, the vacuum must be plugged back into its charger and allowed sufficient time to charge before further use. This makes it impractical for long vacuuming jobs. Depending on the specific cordless vacuum you choose, you may get between 10 minutes to several hours of use when the battery is fully charged. The other reason a cordless vacuum may not be practical for vacuuming an entire home is that they tend to have smaller trash compartments, so you may have to stop half-way through to empty the compartment or change the bag.