Will my mobile phone work in Europe?
Your mobile phone should work in most countries throughout Europe, especially if it's relatively new (made within the last 5 years or so) as most models are compatible with the continent's cellular networks. If you're travelling from countries such as Australia, the United States, Canada, and New Zealand (among others), you should have no problem staying connected during your travels with a number of options available when it comes to internet access. These options include activating your mobile provider's international data roaming plan (this is usually an additional fee on top of your plan), connecting to the local Wi-Fi, or purchasing a local SIM card in your European destination if your phone is unlocked.
Most European countries use the Global System for Mobiles or GSM network, as do a whole heap of other countries around the world. This is one of the main reasons why, as long as your phone is operating on the same network, you shouldn't come across any usage issues when travelling. However, there are some exceptions to this. If your phone is operated using the CDMA technology (Code Division Multiple Access), which is a common network in the United States, then it won't work in Europe. Make sure to contact your local mobile provider if you're unsure what network your phone uses before you arrive in Europe to avoid any complications.
Buying a SIM card in Europe
Buying a SIM card is by far one of the best ways to stay connected throughout your travels in Europe as you don't need to rely on local Wi-Fi access at hotels or restaurants and you won't have to pay extra roaming fees. It's also incredibly easy to purchase one with most mobile providers having stores in all international airports. The most popular providers in Europe are Orange, Vodafone, T-Mobile, and A1 and they all offer relatively good deals on prepaid packages and excellent coverage.
If you don't happen to pick one up at the airport, you can also go to any convenience store, post office, newsagent, department store, or standalone phone store to purchase one. These SIM cards can cost as little as USD$5 for 200 minutes of local calls and 10GB of data (enough for you to surf the internet, access maps, and upload photos to social media) or USD$10 for a more in-depth plan. But you can also purchase more credit at any store where SIM cards are sold if you do run out during your travels.
What's the coverage like in Europe?
European countries generally enjoy excellent coverage (with a rate of around 98%), especially in all major cities so you shouldn't have trouble sending/receiving calls or accessing the internet. However, your phone's strength and signal may vary when you move around each individual country itself with rural or remote areas unreliable when it comes to coverage. It's best to keep this in mind and pre-download any maps or important documents you might need in case you get stuck somewhere with no internet access.