Voyager, traveler, explorer, adventurer, and navigator all describe someone on a journey, but each carries a different emphasis. A traveler is the most general term — anyone moving from place to place for any reason. A voyager specifically travels a long distance, usually by sea or into space, and the word carries a slightly old-fashioned, romantic feel. An explorer focuses on discovery — the journey is a means to find new places or knowledge. An adventurer seeks excitement and risk as the main goal, with the destination secondary. A navigator emphasizes the technical skill of plotting and steering a course. You might say: 'Zola was a seasoned traveler who took trains across Europe, but her great-grandfather had been a true voyager, crossing the Atlantic in a wooden ship.' And: 'The navigator plotted the route while the adventurer climbed the mast for a better view.'
From Old French 'voiage' (journey, travel), which comes from Latin 'viaticum' (money or provisions for a journey), rooted in 'via' (way, road). The word entered English in the 15th century and originally referred to sea travellers. The NASA Voyager spacecraft, launched in 1977, gave the word renewed prominence in the context of space exploration.