Originally Posted by
planko
If you buy a $5 Ventra single-ride TICKET (not card) from a Ventra Vending Machine at O'Hare, that ticket includes the first ride and two transfers at no additional charge. However, the ticket is not valid on Pace, so it won't work if you need to transfer to a Pace bus. If you pay any other way, It's $5 for the first ride (when boarding at O'Hare) plus 25 cents for the first transfer to a CTA vehicle or 30 cents for the first transfer to a Pace bus. The second transfer is free (CTA or Pace).
For those not from Chicagoland, when people in Chicago say "the CTA," most are referring to the "L" trains, even though the Chicago Transit Authority also operates buses. Once inside, you can freely "transfer" from one CTA train to another at no additional cost, on an unlimited basis and regardless of line, just so long as you don't need to leave the system to do so. For example, there's a free transfer tunnel that connects the
Jackson/Dearborn Station on the Blue Line to the
Jackson/State Station on the Red Line; and it doesn't cost anything to to transfer between the two at this location:
Bonus fact: In the
State Street Subway section of the Red Line, all stations from Lake Street to Jackson Street share a single platform. It's the longest subway platform in the world and the longest train platform in North America. Chicago Aussie made an interesting YouTube video about it: