Simplify the following text for a Grade 9 native English-speaking person.
Original: Glasgow International Airport ( formerly Glasgow Abbotsinch Airport ) is an international airport in Scotland , located 8 m south west of Glasgow city center , near the towns of Paisley and Renfrew in Renfrewshire .
Simplified: Glasgow International Airport is the most-used airport in Scotland , which is located 8 miles south-west from Glasgow city center .