It's so hard to do steemit for the first time. Is there anyone who can give me basic knowledge and concepts of terms like steemdollar, steempower, and vote witnesses? ( ͒˃̩̩⌂˂̩̩ ͒)( ͒˃̩̩⌂˂̩̩ ͒)( ͒˃̩̩⌂˂̩̩