The phrase "several continents" means more than one large landmasses on Earth. It refers to different parts of the world that are separated by oceans or seas. Full definition
The common scientific belief has been that army ants originated separately on several continents over millions of years. (news.cornell.edu)
But you're managing multiple brands across several continents. (canadianbusiness.com)
I've traveled over several continents with it and the battery lasts so long on a charge I normally don't need to even charge it while traveling for two weeks at a time. (thewirecutter.com)