Is printer paper a4 or letter?

Is printer paper a4 or letter? What exactly is A4 paper, and why does it have a different name than the "standard" paper size?

A4 Size Paper, Quill Paper Buying Guide

A4 vs Letter: What Is The Difference Between A4 And US Letter Size?

Printer paper sizes explained: Printing Basics 101

🔥Free Storage Bag】Letter & A4 Paper for M08F

Is printer paper a4 or letter?

What are the causes and effects of global divides? - Quora

Paper Sizes and Formats, the Difference Between A4 and Letter

What's The Difference Between US Letter and A4 Paper Sheets?

Premium Paper for Letter Head Printing A4 Size, 125 Gsm , Smooth Finish, 8.25 x 11.75 Inch, White, Pack of 100 Multipurpose Paper

【No Paper Jams and Easy to Tear】 The Folded Thermal Paper has Jagged Edges Between Each Page, Making A4 Thermal Paper Easy to Tear Apart, and Foldable

PeriPage 100 Pages Folded A4 Thermal Printer Paper for Long-lasting, 8.5 x 11 Inch US Letter for A40 Portable Printer and Brother PocketJet

Stationery difference - The Norwegian American

Printer Paper Buying Guide

Printer News, Large Print News