LETTERS

Letter     

1. A letter is any character that is not considered a number or symbol. For example, a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, and z are all lowercase letters in the English language and letter keys on the keyboard. In the image to the right is an example of the uppercase letter 'A'. 

2. Letter also describes a paper format, see the A4 definition for further information on this term. 

3. Lettering is the process of inscribing letters onto or into something. For example, inscribing letters into wood or embroidery letters are both examples of lettering. 

4. A letter describes a message from one person to one or more other people.


CARDS

     A card (or expansion card , board , or adapter ) is circuitry designed to provide expanded capability to a computer. It is provided on the surface of a standard-size rigid material (fiberboard or something similar) and then plugged into one of the computer's expansionslot s in its motherboard (or backplane ). Cards may come in one of two sizes designed to match standard slot dimensions. A card can actually contain the capability within its circuitry (as a video card does) or it can control (through an extended connection) a device (such as a hard disk drive).