Most major carriers allow you to use your compatible smartphone to act as a mobile hotspot. You just have to turn your phone on as a hotspot and connect to it via your wireless device.
However, as of this writing, I carry my mobile phone as a hotspot, as well as carry 2 additional mobile hotspots depending on whether I’m traveling in Europe or in the Americas.
If you decide to use your phone as a mobile hotspot when traveling overseas, be sure your plan includes data roaming, otherwise you’ll be racking up a huge bill.