What are they and how do they work?
It is a digital or virtual currency- a completely virtual type of money. It is basically cash in online form or version. One can use them for many purposes like for example to buy services or products, however not all shops have started to accept them yet and some of the countries banned them altogether. The physical ones you see in photographs are just a novelty. The bonus bitcoin is completely worthless if certain private codes are not printed in them.
Are bitcoin secure to use?
It is extremely difficult to make fake coins, spend the coins not owned by you or copy them because every single transaction is publicly recorded. Every coin has a private key or secret password kept inside a digital wallet, which allows the cryptocurrencies to be spent and transacted. Hacking them is a popular crime among the hackers because if the information of the key is let out or compromised, the hackers can transfer all of the coins of the victim to themselves or simply eliminate all the digital coins by deleting the key.
Since they are not controlled by the banks or the government people seem to really seem to fancy the idea of them and try to collect more of them. Moreover, they can also be spent anonymously. Even though the transactions are recorded, no one can know the account number used until and unless you already told them.