It is like a government election. You vote on the people who represent the steem network. So if you vote me as a witness, you trust me to make decisions that are good for the network.
This affects new user signups, bandwidth, steem price, SBD interest rate and that the network is stable and free. Witnesses are the ones to decide these things and the gatekeepers who accept/reject updates to the blockchain. So you want to vote witnesses you trust and who you feel make good decisions.
Thanks for the knowledge sharing of Witness System. Will vote for you.
Have a great day and stay blessed.