(portable document format) a way of storing computer files so that they can be easily read when they are moved from one computer to another 可移植文件格式
From Longman Business Dictionary
PDFPDF noun [countableC, uncountableU]COMPUTING
portable document format; a way of storing computer files so that they can be read using any computer system. PDFs can be sent from one computer to another and always look the same on every computer
The PDFs are on the U drive if you want to look at them.