listtransactions will list transactions only involved with me? Will listtransactions list all transactions from blockchain, or only list transactions involved with me?

I have checked bitcoin wiki, it's only saying that it will return recent transactions from "all accounts". What does "all accounts" mean? does it mean all MY accounts? or it will include accounts of other people?
"listtransactions" will list all the transactions associated with your specific bitcoin wallet.  The "All Accounts" business, I believe, has to do with the various addresses someone could have withing a single wallet.  

For example, I have an address where I receive donations, and a different address where I receive mining payouts.  by default "listtransactions" will list all my transactions from both addresses, however, I could specify one of my addresses and it would list only those transactions.  It's an easy way to get more granularity in the lists and organize your data better.