ype, What is it made from

Type is the single piece of metal bearing a character of the alphabet or number. Typemetal is an alloy made mostly from Lead with Antimony and Tin added to it for strength (2 to 5per cent tin and 10 to 13 per cent Antimony for slug casting machines and 10 to 25 per cent Tin and 20 to 30 per cent Antimony for founders type). In manufacture type is cast accuratly to allow all the characters in a Fount to align correctly, The Diagram below shows a piece of type with all its features marked

The names of the constituent parts of a piece of type are quite distinct and vary from face to face. The face referred to as a serif or sans serif face can be Normal, Bold, Italic, Bold Italic each is kept in separate trays or cases. It is normally Italic faces that have Kerns, these are the overhang of the extremes of the character to the body, this is supported by the previous or next piece of type. The terms used in printing has led to a wealth of jokes regarding a printers anatomy, one such joke is pictured on this link Cartoon
Most of the styles of typeface are self explanitary, Roman, Italic, Bold, Sans Serif and Display faces. All have there uses and times for use, personal preference is everything when it comes to choice of face.
Type size (measured in points where 1 point is 1/72nd of an inch) refers to the body size (item 16 above) and will cover the range from the top of the ascenders to the base of descenders in any face (top of a  capital letter to the base of a g or y ie. Afg).  A roman face is normally serifed (eg. Times) unlike a sans serif face (eg. Arial)