Lives are the number of tries you get to beat levels. You can have a total of five, and you lose one every time you lose a level. It takes 30 minutes to refill one life.
You can see how many lives you have and how much time you have left until one is refilled in the top left corner of the farm screen.
You can also use coins to refill your lives or ask friends to send you some.
To request or send lives, tap the lives icon in the top left corner of the farm screen.
You can send lives to each of your friends, with or without a request, only once a day. You can accept the lives sent to you when you have less than five. You can ask for lives once a day at any time. Please note that the envelope only appears on the lives icon when you have less than five lives or when your friends ask you for them.
IMPORTANT! If your friend sends you an extra life when you already have the maximum of five or unlimited lives, you'll be still able to use it later—it won't disappear.