A ticket is a means of advancing to the next episode in Candy Crush Saga. From episodes 3 to 64, you must wait 72 hours, or else three tickets are needed from three different friends playing the game in order to proceed to the next episode. The best alternative option to get to the next episode are to go on three mystery quests (for mobile only).
It is not recommended to ask tickets to friends, unless you do not have a device that can play the game on the app/mobile platform. Mystery Quests are recommended instead: to access them, turn off all internet (temporarily), and then go to the "ticket level". You can also override the timer limit by setting the clock forward, and then returning it back to its original state.
For web platforms, a ticket is first requested at the end of the 2nd episode, Candy Factory to unlock the 3rd episode, Lemonade Lake. However, in mobile versions, it is first requested at the end of Lemonade Lake to unlock the fourth episode, Chocolate Mountains. After this, to unlock the next episodes, three tickets are needed each time. Mary helps to unlock the episode after 72 hours, or three days (There may be a glitch with the time-elapse method).
Sometimes on web version, there is a golden ticket available for purchase with real money. Buying this will unlock any possible episode of your progress.
No tickets are needed in Dreamworld to advance to the next episode, but you must complete the Reality counterpart before you can play the Dreamworld episode.
Tickets are not required since the 64th episode, the Minty Meadow scene and the first episode released after the end of Dreamworld.
On web version, if the portal requires a ticket, the picture of the corresponding players helping you will be shown on the portal. If the help does not come from a player (i.e. unlocked by time or playing on mobile with mystery quests), the icon of Mary will be shown instead.