what is a hoverboard?? it is safe??how much it costs??is it legal?? ........

First things first: What exactly is a hoverboard?

These hoverboards can't actually levitate, a la "Back to the Future Part II." Instead, they use wheels to roll across the ground. It sounds lame, but really, they're far more fun to ride than a skateboard. Ignoring the reality, the hoverboard moniker has stuck in pop culture. So for this article, that's what I'm calling them.
The more accurate name is "self-balancing scooter," and what you get is a two-wheeled motorized gadget. These scooters look and work like miniature Segways, minus the handlebars, moving forward when you lean forward and braking and reversing when you lean back. And as with a Segway scooter, you face forward while riding, instead of facing to one side as you would with a skateboard. You control and steer them with subtle movements of your feet, legs and torso.
Hoverboards have two pressure-sensitive footpads that control your speed and allow you to steer with your feet. The boards begin moving when you step on, which makes them tricky to mount and dismount. Because there is no handle to steady yourself, getting your balance can be tough and it's easy to fall off while you get used to the board. You'll use your core to keep yourself balanced and also feel the burn in your calves and feet, since the muscles in those areas help you steer.

Hoverboards don't actually hover. They roll. James Martin/CNET

What's up with hoverboards catching fire?

There have been reports in 2015 of hoverboards combusting or exploding, and the culprit seems to be faulty batteries. Hoverboards are powered by large lithium ion batteries that can overheat and explode under rare circumstances.
Some reports suggest that these faulty batteries are an issue particularly with cheap, generic boards you can find on eBay and Alibaba for under $300. However, the Consumer Product Safety Commission is investigating the safety of all hoverboards across all brands, trying to understand why the fires and explosions are happening. Until the investigation is complete, we won't know for sure which brands are prone to disasters. In the meantime, to minimize the risk of a fire, experts recommend not charging a hoverboard overnight or while away from your house.
Another issue to be aware of is counterfeit boards available through third-party sellers on Amazon or eBay. CNET video producer Mariel Myers encountered this when she purchased a Riorand board from a third-party seller via Amazon and ended up with a cheaply made fake. These knockoff boards may be more prone to fires and explosions, but we don't know for sure. To get the real board, she ended up going directly to the Canadian manufacturer's website.
The rule of thumb is to buy a hoverboard directly from the manufacturer to minimize the risk that you'll get a fake. (See "What are the differences between the top hoverboards?" below.) That said, buy and ride at your own risk because there's no guarantee that any hoverboard won't catch fire or explode.

Hoverboards are sold by many companies, and it's hard to know which ones are safe. James Martin/CNET

What are the other safety concerns?

Riding any kind of vehicle, whether it's a skateboard, bicycle or hoverboard, can put you at risk for injury. Hoverboards can reach a maximum speed of around 10 mph, so you could sustain a more substantial injury than you would falling off a slower-moving skateboard.
Proper safety gear is a must while riding, including helmet, knee pads, elbow pads and wrist guards. This will lower your risk of fractures, sprains and other injuries if you fall.
As with bikes and skateboards, there's also a risk of getting into a traffic accident, especially if you're in or close to the street. A teen was struck and killed by a bus in London while riding a hoverboard. Please, don't ride a hoverboard in the street or near traffic.
Hoverboards have minimum and maximum weight limits, which are meant to protect the rider and scooter. Most boards also won't operate going up or down steep hills, usually over 30 degrees. There are no height limits associated with the boards, though keep in mind that most lift you about four inches above the ground. If you're particularly tall, you'll run a greater risk of hitting your head while riding.
Here's a breakdown on the weight and slope restrictions for the popular models.

	IO Hawk	Phunkeeduck	Monorover R2D	Swagway	Powerboard
Maximum weight	280 lbs (127 kg)	300 lbs (136 kg)	250 lbs (113 kg)	220 lbs (99 kg)	220 lbs (99 kg)
Minimum weight	45 lbs (20 kg)	45 lbs (20 kg)	Not specified	44 lbs (19 kg)	45 lbs (20 kg)
Steepest incline it can handle	35 degrees	35 degrees	40 degrees	30 degrees	Not specified

Only Powerboard specifically states that children under age 13 shouldn't ride on its boards. Most other manufacturers don't have explicit age limits; the Swagway and Phunkeeduck user manuals merely state that children, pregnant women and the elderly should not ride the scooters.
Children under the weight limit for these hoverboards will have trouble riding, since the scooters won't detect their weight and won't balance correctly. As to whether your kid should ride a hoverboard, you parents and guardians will have to use your best judgment.

Hoverboards range in price from $400 to $1,800. James Martin/CNET

What are the differences between brands?

There are many different companies selling hoverboards, starting around $400 and reaching up to $1,800. Many of them work just the same, with minor differences in specs and style. I've ridden several models. While there are subtle variations in how they ride, it's not easy to tell apart the high-end and less costly versions.
The biggest factor to consider when shopping is price because most hoverboards have similar specs. Nearly all can carry the same weight and have similar maximum speeds. Check out a comparison of the big-name models below, including IO Hawk, Phunkeeduck, Monorover, Swagway and Powerboard by Hoverboard.
That said, note that CNET has not thoroughly tested any of these brands, nor can we specifically vouch for their relative safety or lack thereof.

	IO Hawk	Phunkeeduck	Monorover R2D	Swagway	Powerboard
Price*	$1,799 (around £1,200, AU$2,500)	$1,499 (around £1,000, AU$2,070)	$599 (around £400, AU$830)	$399 (around £266, AU$550)	$499 (around £333, AU$690)
Colors available	Black, white, red, blue and yellow	Black, blue, orange, pink, red, silver, white and yellow	Black and white	Black, white, red, dark red, green, blue and pink	Black, white, blue, red, green, pink, silver and gold
Warranty	One year	One year	One year	One year	One year
Weight	22 lbs (9 kg)	18 lbs 8 kg)	22 lbs (9 kg)	22 lbs (9 kg)	26 lbs (11 kg)
Maximum speed	6.2 mph (9.9 kph)	12 mph (19 kph)	9.5 mph (15 kph)	10 mph (16 kph)	6.5 mph (10 kph)
Range	8-12 miles (12-19 km) on full charge	10 miles (16 km) on a full charge	11-15 miles (17-24 km) on a full charge	Up to 20 miles (32 km) on a full charge	6 hours of riding time on a single charge

*All prices are given in US dollars and converted to other currencies.

Where can I actually ride one?

Hoverboards are cool, but some states, countries and airlines aren't so excited about them. It's illegal to ride one on public roads or walkways in New York State, Australia and the United Kingdom. Many schools (including UCLA), malls, airports and other public places are banning hoverboards as well.
Before you pack one for a flight, know that most major airlines have banned hoverboards. American, Delta, United, Jet Blue, Southwest, Hawaiian and others have put out advisories stating they are no longer allowing them in checked or carry-on luggage.
On the flipside, California lawmakers recently signed a bill that allows motorized wheeled devices, including hoverboards, anywhere a bicycle can go, including bike lanes on streets.

Hoverboards are banned in many places, but California signed a law making them legal in bike lanes. James Martin/CNET

I still want a hoverboard. Where can I buy one?

Hoverboards rose in popularity over the summer and were easy to buy nearly anywhere. Now, they're a little harder to find.
Your best bet to buy a hoverboard is to go to the manufacturer's website to ensure you get a quality product and get a warranty that protects you from defects and disasters.
Overstock.com stopped selling the boards over safety concerns. Amazon pulled the listings of many popular hoverboards off its site but wouldn't comment on the decision. Currently, Amazon is not selling boards from Phunkeeduck, IO Hawk or Monorover, though other models, such as the Hover X and Razor Hovertrax are still available.
Following suit, Target is no longer selling Swagway hoverboards on its website. Even the US Postal Service is wary of hoverboards and will only ship them via ground transport, instead of putting them on planes.

Why are they so popular?

Hoverboards are challenging but fun to ride. They can be tough to get the hang of. But once you master riding one, it moves seamlessly with you, stopping on a dime and turning easily. Riding one almost feels like an extension of yourself, and it doesn't require any manual motion, like a skateboard or kick scooter. You can pick up a lot of speed (again, most top out at about 10 mph), making them faster than walking.
Celebrities have also flocked to hoverboards, which has upped their popularity. Singers Justin Bieber and John Legend have been seen riding them. Rapper Wiz Khalifa was arrested while scooting around on one in the Los Angeles Airport. Though they can be expensive, they're smaller and cheaper than a Segway (which costs upward of $5,000), so they're much more accessible to buy, store and use.
Hoverboards may be a tech fad in 2015, but there's a chance they're here to stay through the next year at least. Expect newer versions in 2016, and perhaps they will show up on shelves at a store near you.