I am new to Bitcoin and have gone through a couple of video introductions and articles. I have few questions on Bitcoin transactions:
1) I read that the sender needs to encode the numbers of remaining Bitcoins with him in the transaction. This is to say if Alice has 50 Bitcoins and she wants to transfer 40 to Bob, her transaction data would have two destinations: 40 BTC to Bob's address and 10 BTC to Alice. But I looked at the below link with transaction data:
This does not have any case where the sender is same a recipient. Is it that this info is excluded for web reporting or am I missing something.
2) How are the number of transactions in a block decided? I know that block size has a limit but how is it determined which transactions would a block pick from pool of unconfirmed transactions?