From Wikipedia:
“Overlanding is self-reliant overland travel to remote destinations where the journey is the principal goal. Typically, but not exclusively, it is accomplished with mechanized off-road capable transport (from bicycles to trucks) where the principal form of lodging is camping, often lasting for extended lengths of time (months to years) and spanning international boundaries.”
From the Overland Journal:
“Overlanding describes self-reliant adventure travel to remote destinations where the journey is the primary goal. Typically, but not exclusively, accommodated by mechanized off-highway capable transport (from bicycles to trucks) where the principal form of lodging is camping; often lasting for extended lengths of time (months to years) and often spanning international boundaries. While expedition is defined as a journey with a purpose, overlanding sees the journey as the purpose.”