When you are going travel, you must exchange some local currency and put them in your wallet.
Now, you can shop online and buy different products in different countries anytime, and all you need is some cryptocurrency - Bitcoin.
Bitcoin is the most common used and you can found where to spend them in the "Shopping with Bitcoin"
To own a Bitcoin wallet, all you need is a mobile phone, tablet or any computer.
There are many types of wallets such as coinbase, hive wallet, ...etc.