档案(dàng àn) - file, archive, record in Mandarin

档案 (dàng àn) is a file in the sense of a dossier: the folder of records an employer, a school or the state keeps on a person or a project. The measure word is 份 for one document set and 个 loosely in speech.

In mainland life the word has a specific weight. Your 人事档案 is the personnel file that follows you between employers, and losing track of it is a real administrative headache. That institutional flavour never quite leaves the word.

The trap is computing. On the mainland a file on your hard drive is a 文件; 档案 in that sense is standard in Taiwan and reads slightly foreign in Beijing. Use 文件 for the thing you double click and keep 档案 for the folder in the filing room.