Brackets

the punctuation marks '{' and '}' used in pairs to set apart or interject text within other text

Case

in typography, this is the distinction between capital (big) and lower (small) letters

/ (forward slash)

a key used to separate folders and files, often used in Unix file systems

> (greater than sign)

the sign which means that the value on the right is less than the value on the left

5 > 3

< (less than sign)

the sign which means that the value on the left is smaller than the value on the right

3 < 5

- (minus sign)

The operator sign often indicating the process of subtraction or difference

Parentheses

the punctuation marks '(' and ')'used in pairs are often used to group values in an equation.

% (percent sign)

the sign meant to show a common measurement based on a fraction of 100

+ (plus sign)

the operator sign normally indicating the operation of addition

Square brackets

the punctuation marks '[' and ']' used in pairs to set apart or interject text within other text

~ (tilde)

this key normally means "approximately" in mathematics; in Unix systems this character is used to represent a home directory

_ (underscore)

a character often used in file names to join words without using a space; originally used on typewriters to make underlined text