Brno is the second largest city in the Czech Republic.
The whole region is divided into zones, so when you buy a ticket, you must buy it for time period, and for zones, which you can go through. Brno has 2, 100 (center) and 101 (suburbs).
One 60min ride in public transport around whole Brno is 25CZK/1EUR (you can transfer within the time limit as much as you want). 24h ticket for Brno costs 90CZK/3,5EUR. Here is link to the public transport system, where are all the informations, the price list is here.