Lots of people thinks that Blockchain is a database, actually its not. Blockchain is a digital ledger where any transaction can be processed related to Finance, Medical, and any field which include value
Actually, a blockchain is a
data structure.
It is, in bitcoins case, a public ledger. But it doesn't have to be (1) public, neither does it have to be a (2) ledger.
The basic idea behind the blockchain is to create an immutable structure of 'blocks' refering to the previous one, creating a 'chain'.
What kind of data is going to be stored inside of a blockchain, is completely up to the application utilizing this technology.
Yes that's true. Adding to it, it depends from blockchain to blockchain as to what type of data we can feed into the blocks.
I have read somewhere that a blockchain can contain any type of file but it will be in a hexadecimal format. Hence the hashes will be then added to the blocks. Also, the blockchain was introduced to make payments efficiently and hence it is not recommended, though possible, to enter other type of data into the blockchain except transactions.