You can vote for 30 witnesses.

• Click on the hamburger icon to the right of your icon at the very top right of any post.
  • Click on Vote for Witnesses
    • Vote for up to 30 witnesses.
• Please note: you can also vote witnesses that do not show up on this page.
  • You might want to see @ura-soul's post about this situation
    • You vote for those not showing up on that page by entering their name at the bottom where it says
      If you would like to vote for a witness outside of the top 50, enter the account name below to cast a vote.

The idea of the witnesses is they represent you to Steemit, Inc.

• So try to pick witnesses that are doing a lot for the entire Steemit platform.
  • many have external websites that are very useful
  • They all must run a server that supports the blockchain.
    • They make money for doing this.
      The higher they are on the list, the more money they can make.
      So by voting for those doing a lot for the platform, you are helping them do even more for the platform...