Hiking is typically a shorter walk in nature for pleasure—often a few hours to a full day—on marked, established trails that vary in difficulty. You usually return to a trailhead or nearby lodging the same day, carrying light gear such as water, snacks, and layers.
Trekking is a longer, more demanding multi-day journey on foot through rural or wilderness terrain, often toward a specific destination. It usually involves overnight stays in camps, huts, or simple lodges, more rugged or remote routes, and heavier preparation for fitness, weather, and gear.
In short: hikers enjoy the trail for a day; trekkers commit to a self-contained, multi-day expedition. Regional usage overlaps, so check duration, terrain, and overnight needs rather than the label alone. Source: Intrepid Travel.