bandwidth is your power to do ANYTHING on steemit, post, upvote, comment, transfer funds, power up, etc. If you read the first of those articles I shared, you'll understand it better. Your bandwidth is related to your SP, which you have very little of in the beginning, unless you invest cash. No, it does not help. If you run out, you'll be stuck, with nothing to do but wait for it to power back up sometimes a day or more.