Paper is typically grouped into two main grades based on weight and thickness: Text and Cover.
Description of  Text Papers
"Text" is a generic name for a variety of light, thin paper stocks that includes Book, Bond, Writing, Ledger, Offset paper.
Text paper is flexible, is easily rolled and folded, and is used for flyers, handouts, letterheads, and books. For example, the paper used in ink jet printers is considered Text.
Description of Cover Papers
"Cover" is a generic name for a variety of heavier and thicker paper stocks that includes Bristol, Index, Tag, and Card paper.
It is more substantial and durable than Text paper. Cover paper is more rigid and must be scored (creased) before it can be folded.
Cover papers are typically smooth but there are textured variations. It can have either a matte or glossy appearance.
Cover or Card stock is often used for mass mailed postcards, business cards, playing cards, invitations, program covers, greeting cards, door hangers, catalogue covers, presentation covers, scrapbooking, folding cartons, packaging, retail displays, and more.