As a simple definition - It's traveling from one location to another while carrying everything you will need to survive with you.

A more technical answer - overlanding is a form of self-reliant, long-distance travel from Point A to Point B through mostly remote areas on unpaved or unimproved road surfaces. It also generally involves multi-night camping. Modern-day overlanding involves traversing rugged terrain in a truck camper or equipped rig that can handle rough roads over long distances. Although most enthusiasts recommend using a 4-wheel-drive (4WD) vehicle, you can overland with 2-wheel-drive cars that are less capable than trucks or SUVs. That said, overlanding without 4x4 vehicles can be challenging, especially if off-roading becomes necessary along the way.

Overlanding is as much about the journey as it is about the destination. One can measure trips in days, weeks, or even months. Notable overlanding routes across the globe include the Silk Road (from China to the Mediterranean Sea); Cape Town to Cairo in Africa; and Yellowknife, Canada, all the way down to Tierra del Fuego at the southern tip of Chile to cover the Americas. Overlanders strive for self-sufficiency, carrying gear, supplies, and equipment for extended off-grid travel. They bring food, water, and shelter for daily survival. Instead of traveling lightly and quickly, overlanding is slower, more calculated, and more planned.