The Czech Republic’s main airport is Ruzyne Airport in Prague. Daily flights from most European cities fly to this airport. Airports in the country’s other cities, Ostrava and Brno only serve domestic flights. There are many overland ways to enter the country with over 30 routes on rail and 18 routes via road.
If you have the money to fund them, flights can be purchased for internal flights between Ostrava and Brno. The easiest way to travel around (if you decide not to be a high flyer) is by train which is cheap and a good way to see parts of the countryside (which is very scenic in the Czech Republic). They also serve nearly every nook and cranny of the country. Buses are cheaper, and sometimes cheaper.
Prague is served by a subway (metro) system along with buses and trams.