I have no clue what MultiPlex theaters are

So back in the earlier days of cinema, you’d go to the Cineplex to see a movie. A Cineplex would only have a single screen for viewing movies while the multiplex would have multiple screens for seeing movies on. This started with the first duplex theatre in 1915 and later the first triplex in 1966, shortly followed by theatres with 6+ screens which is around when the term “multiplex” started being used. Basically for anyone born after the 80s (therefore anyone under the age of about 40) the term is largely obsolete since most theatres have at least 4 screens and qualify as multiplexes, plus the industry has seen so much consolidation that smaller independent theatres with 1-2 screens are pretty uncommon now