Type Anatomy

Characters

The basic typographic element is called a character, which is any individual letter, numeral, or punctuation mark. The capital letters are called caps, or uppercase (u.c.) characters. Small letters are called lowercase (l.c.) characters. Numbers are called numerals or figures.

Character components

Typographic characters have basic component parts. The easiest way to differentiate characteristics of type designs is by comparing the structure of these components.

Ascender
The lowercase character stroke which extends above the x-height.
Bar
The horizontal stroke on the characters ‘A’, ‘H’, ‘T’, ‘e’, ‘f’, ‘t’.
Baseline
The imaginary horizontal line to which the body, or main component, of characters are aligned.
Bowl
The curved stroke which surrounds a counter.
Bracket
A curved line connecting the serif to the stroke.
Counter
The empty space inside the body stroke.
Descender.
The lowercase character stroke which extends below the baseline.
Loop 
The bottom part of the lowercase roman ‘g’.
Sans serif
From the French, meaning “without serif”. A typeface which has no serifs. Sans serif typefaces are typically uniform in stroke width.
Serif
Tapered corners on the ends of the main stroke. Serifs originated with the chiseled guides made by ancient stonecutters as they lettered monuments. Some serif designs may also be traced back to characteristics of hand calligraphy. Note that serif type is typically thick and thin in stroke weight.
Shoulder
The part of a curved stroke coming from the stem.
Stem
A stroke which is vertical or diagonal.
Terminal
The end of a stroke which does not terminate in a serif.
X-height
The height of the body, minus ascenders and descenders, which is equal to the height of the lowercase ‘x’.
X-heights vary among typefaces in the same point size and strongly effect readability and gray value of text blocks.
Stress
The direction in which a curved stroke changes weight.

                  Sources: http://graphicdesign.spokanefalls.edu/tutorials/process.htm