The most important airports are Frankfurt (IATA: FRA), Munich (IATA: MUC) and Düsseldorf (IATA: DUS).
Berlin-Tegel (IATA: TXL), Cologne (IATA: CGN), Hamburg (IATA: HAM) and Stuttgart (IATA: STR) serve some international flights as well.
Frankfurt is Germany's main hub - one of Europe's four major hubs - and the destination of most intercontinental flights. Munich is a growing secondary hub. Travellers can easily fly in from most places of the world and then connect with Germany's biggest and most respected airline Lufthansa, which is a member of the Star Alliance. Germany's second largest airline is Air Berlin, a member of the Oneworld airline alliance, which also serves lots of destinations throughout Germany and Europe (and some worldwide) from several airports.
The airports of Frankfurt, Düsseldorf and Köln/Bonn are connected to the InterCityExpress high speed rail lines. The others all feature either a commuter rail station or some sort of connection to the nearest rail station as well as public transport to the central station of the respective cities. Lufthansa's passengers travelling from Frankfurt Airport have the option to check-in their luggage in Cologne or Stuttgart train stations and connect to the airport by ICE. If doing so, be sure to book the train journey like a Lufthansa connecting flight (ie in advance together with the flight), otherwise you will be responsible for a missed connection.
Budget travel and minor airlines
Flying can be the cheapest way to get to Germany and from there to other European countries, especially if the flights are booked well in advance. Before booking a budget flight, compare carefully as their destinations are often a bit off the track and after adding all the (baggage) fees, taxes, additional bus tickets to get to their airports, you might end up at even higher prices than you would pay for a discounted Lufthansa or Air Berlin ticket.
The major airports for budget travel are Berlin-Schönefeld (IATA: SXF), Frankfurt-Hahn (IATA: HHN) (130 km to Frankfurt) and Weeze (IATA: NRN) (85 km to Düsseldorf) as well as smaller airports with fewer choice of destinations like Lübeck (IATA: LBC) (70 km to Hamburg) or Memmingen (IATA: FMM) (110 km to Munich).
There are budget flights to almost every city in Europe from Germany. The major budget airlines in Germany are easyJet, Ryanair, germanwings (for flights within Germany, too) and Wizz Air (for flights to Eastern Europe) which all offer several connections to many countries throughout Europe. The main hubs are Berlin-Schönefeld and Dortmund for easyJet, Frankfurt-Hahn and Weeze for Ryanair, Cologne/Bonn and Stuttgart for germanwings - all of these airlines serve other airports within Germany as well, but with a smaller choice of destinations.
For (budget) flights to European holiday destinations, for example round the Mediterranean, Germany's major carriers besides Air Berlin are Condor (Thomas Cook) (also for main tourist destinations throughout the world) and TUIfly.
Germania, InterSky and OLT have also a limited number of international destinations.
There are also several European high speed trains to cross into or get out of Germany:
The ICE brings you at 300km/h top speed from Frankfurt (3. 3h), Cologne (2. 5h) or Düsseldorf (2. 3h) to Amsterdam. The train journey from Frankfurt to Paris (320km/h) using the ICE will take about four hours; going from Hamburg to Paris can take eight and a half hours.
The Thalys brings you from Cologne (Köln) to Paris in approximately 4h and to Brussels in about 2 hr.
The TGV brings you from Marseille, Lyon and Strasbourg to Frankfurt and from Paris to Stuttgart and Munich.
Standard rail fares are quite high, but there are a number of special fares and discounts available - see the "Get Around" section for more information. In particular, the Bahncard reduction applies for the whole journey as long as it starts or ends in Germany.
Due to the large number of immigrants from the former Yugoslavia, every major bus company from those countries serves routes to (mostly Southern) Germany. From Bosnia and Herzegovina these include Salinea, Prosic and Globtour; from Croatia you can come with Čazmatrans and from Serbia you can choose Panonijabus, Niš-ekspres and others. See also bus travel in the former Yugoslavia.
Lübeck and Sassnitz are connected to Russia's Kaliningrad and Saint Petersburg. Sassnitz is also connected to Rønne (Denmark), Riga (Latvia) and Trelleborg (Sweden).
Kiel has connections to Gothenburg (Sweden), Klaipeda (Lithuania), and Oslo (Norway).
Rostock has connections to Helsinki (Finland), Trelleborg (Sweden), Liepaja (Latvia), and Gedser (Denmark).
Travemuende has connections to Helsinki (Finland), Malmo (Sweden) and Trelleborg (Sweden).
Puttgarden is connected to Rødby (Denmark).