You would do well not to take advice from anybody that has an advertisement in their signature space on this forum.
The vast majority of those are people that are being paid per post to advertise with those signatures. Therefore, they'll say just about anything in a discussion thread just to increase their post count (and therefore increase their income). Generally, they know less about the topic they are discussing than the person asking the questions.
Regarding your original questions:
I am new to Bitcoin. I want to ask some questions that I hope were not asked before. If they were already asked , I am sorry
They were. Many times. It's ok though, I've gotten used to answering the exact same questions hundreds of times. This forum doesn't make it easy to find similar questions that were asked in the past, and most new users find it's easier to just ask the question again instead of putting in the effort and taking the time to search for the previous questions.
1-) In bitcoin mining , actually , we are trying to find a hash that is smaller than a given hash encyrpted by SHA 256 is that correct ?
No.
Mining is trying to find a hash that is smaller than a target value. The target value is NOT "a given hash encyrpted by SHA 256". It is a value that is automatically adjusted by all nodes every 2016 blocks to keep the average rate at which new blocks are solved near 10 minutes.
Also, SHA256 does not "encrypt" anything. It isn't possible to "decrypt" a SHA256 hash. A hash is a "cryptographic" function, but it is not "encryption".
If so , lets say we are given a hash like this 00da3458efac.... , and we found an input that generates a hash , 0034ea873... , after 00 , the first given hash has " da ", and the hash that we found has " 34 " , in hexadecimal system "34" is smaller than "da" , so our answer is correct ? and we win the block to get 25 BTC or one part of 25 BTC if we are in a pool ?
We are not "given a hash". There is a target value, and our computed hash must be less than the target value. I've changed your question here:
lets say we are given a target value like this 00da3458efac.... , and we found an input that generates a hash , 0034ea873... , after 00 , the target value has " da ", and the hash that we found has " 34 " , in hexadecimal system "34" is smaller than "da" , so our answer is correct ? and we win the block to get 25 BTC or one part of 25 BTC if we are in a pool ?
Now with my modified question, the answer to both questions is: Yes.
Not only do you get the 25 BTC, but if you are solo mining you also get all the transaction fees of all the transactions that are included in the block that you just solved. If you are in a pool, then the pool decides what happens with all the transaction fees. They may share them with the miners, or they may keep them. You'd have to check the pool's rules.
2-) Where can I see the latest hash that is given and latest answer ( input ) given, and also , where can I see the given hash that we are expected to find a hash below than?
In bitcoin, there currently are approximately 358142709000000000 hashes calculated every second. Only successful "winning" hashes are given. Everyone just discards all of their failed hashes. They don't bother wasting time and network bandwidth sharing their failed hashes.
The most recent successful hash is stored in the block header of the most recent block added to the blockchain. There are a variety of block explorer websites that provide an interface for you to view the the contents of the blockchain. You could also run your own full node peer on the bitcoin network and get the hash directly out of the block as it is relayed to you.
As an example, you will see at the following link that (as of the time that I am writing this post) the most recent block is block number 363792, and the winning hash value is 0000000000000000112932f093a4ac4c98fb5c9c0052011ad057ceece06fbf81
http://btc.blockr.io/block/info/363792Each block stores a packed representation (called "Bits") for its actual hexadecimal target. The target can be derived from it via a predefined formula. For example, if the packed target in the block is 0x1b0404cb, the hexadecimal target is:
0x0404cb * 2**(8*(0x1b - 3)) = 0x00000000000404CB000000000000000000000000000000000000000000000000
At that btc.blockr.io link I provided, you will see there is data that is named "Difficulty". This is a representation of the "Bits" data. The current difficulty is 49,402,014,931.227. The target value for the hash can be computed from this difficulty number.
1-)
https://blockchain.info/tr/q/latesthash , here I can see only the latest hash but it is not clearified whether it is latest accepted hash or latest given hash below which we are expected to find a hash than.
That is intended by blockchain.info to be the most recent successful hash from the most recently broadcast block.
2-) And , I could not find the list of latest answers , by answers I mean the input data that generates a hash code that is in accordance with rules.
The successful hashes are the SHA256 hashes of the block headers of the blocks that were successfully hashed and added to the blockchain. The input data is the 80 byte block header itself.
No. blockchain.info has bugs in their software and their block explorer is occasionally out of synchronization with the bitcoin network. Frequently their data is incorrect. The most reliable place to get accurate data about the current state of the bitcoin blockchain is by running your own full node peer with the most recent software update, and writing software to extract the blockchain data directly from the blockchain on your node.
