Austrian Blind: A gathered blind made longer than necessary. The extra fabric forms ruching at the bottom.
Blind: A single curtain with a fixed heading which pulls up from the bottom.
Box Pleats: A row of folds in alternate directions. The extra fabric in the folds can be taken either to the front or the back (inverted pleats) for the desired effect.
Double Fullness: When each of a pair of curtains are made to the full measured width of the whole window, enabling curtains to drape in folds.
Drapes: Another name for curtains.
Festoon Blind: Often confused with Austrian blinds, the difference being that a Festoon blind is ruched from top to bottom.
Finished Width: The actual width after the treatment is finished and all allowances have been utilised.
Fullness, or Fullness Ratio: The ratio of fabric width to the width of the window it is to cover. Curtains are usually at least twice the window width.
Heading Tape: A wide woven tape built into the heading, incorporating pockets for the curtain's hooks and gathering cords.
Hold Backs: Decorative hooks fixed onto the wall beside the window to hold curtains back when open (without tie-backs).
Pattern Repeat: The distance one pattern is duplicated down the length of the fabric. Pattern repeat is one full pattern length.
Pelmet: A decorative way of concealing the top of curtains and curtain tracks. Usually a flat shaped panel which can be painted or covered with fabric such as a valance.
Return: The sides of the window treatment that project from the edge of the window along the wall.
Roman Blind: A flat blind that concertinaed up to the top of the window.
Tie Backs: Stiffened shapes of fabric or cord hooked onto the wall to hold curtains back.
Valance: A gathered, and sometimes shaped, mini-curtain hung from a pelmet board to conceal the top of curtains or a curtain track.

Cookie: A message given to a Web browser by a Web server. The browser stores the message in a text file. The message is then sent back to the server each time the browser requests a page from the server.