Le mot anglais pour classeur est
file

Définition en anglais

classeur
1. n-m. file (stationery to keep documents together), binder
2. n-m. ring binder
3. n-m. filing cabinet
4. n-m. workbook
5. n-m. stamp album

folder	©
1. n. Dossier, chemise.
2. n. Informatique (métaphore) dossier.
Which folder is the file in?
3. n. (Rare) Plieur, plieuse (celui, celle qui plie).

folder	©
1. n. An organizer that papers are kept in, usually with an index tab, to be stored as a single unit in a filing cabinet.
I keep all my schoolwork in a yellow folder.
2. n. (computing) A virtual container in a computer's file system, in which files and other folders may be stored. The files and subfolders in a folder are usually related.
My essays are in the folder named "Essays".
3. n. A machine or person that folds things.
4. n. A folding knife.