A Bittrex wallet is a wallet of asset (many cryptocurrency) for trading like you can do on the stock exchange market for example. Bittrex is a platform for trading cryptocurrency and the wallet in Bittrex means your total amount of money for every Coins you have there. On Steemit the wallet is made of 3 currency steem, steem dollar and steem power all these currency are the one you earn in steemit by posting and curating or even buying it,this is not a trading platform. But some currency can be sent from Bittrex or Steem from one to the other. I hope you ubderstand it