cut

Divide a file into several parts (columns)
Writes to standard output selected parts of each line of each input file, or standard input if no files are given or for a file name of `-'.

Syntax
     cut [OPTION]... [FILE]...
In the options below, BYTE-LIST, CHARACTER-LIST, and FIELD-LIST are one or more numbers or ranges (two numbers separated by a dash)

Bytes, characters, and fields are are numbered starting at 1 and separated by commas. 
Incomplete ranges can be given: -M means 1-M  ;  N- means N through end of line or last field.

Options

-b BYTE-LIST
--bytes=BYTE-LIST
     Print only the bytes in positions listed in BYTE-LIST.  Tabs and
     backspaces are treated like any other character; they take up 1
     byte.

-c CHARACTER-LIST
--characters=CHARACTER-LIST
     Print only characters in positions listed in CHARACTER-LIST.  The
     same as `-b' for now, but internationalization will change that.
     Tabs and backspaces are treated like any other character; they
     take up 1 character.

-f FIELD-LIST
--fields=FIELD-LIST
     Print only the fields listed in FIELD-LIST.  Fields are separated
     by a TAB character by default.

-d INPUT_DELIM_BYTE
--delimiter=INPUT_DELIM_BYTE
     For `-f', fields are separated in the input by the first character
     in INPUT_DELIM_BYTE (default is TAB).

-n
     Do not split multi-byte characters (no-op for now).

-s
--only-delimited
     For `-f', do not print lines that do not contain the field
     separator character.

--output-delimiter=OUTPUT_DELIM_STRING
     For `-f', output fields are separated by OUTPUT_DELIM_STRING The
     default is to use the input delimiter.
Example

Parse out column 2 from a semicolon (;) delimited file:

$ cat myfile.txt | cut -d \; -f 2 > output.txt

"It seemed the world was divided into good and bad people. The good ones slept better... while the bad ones seemed to enjoy the waking hours much more" ~ Woody Allen

Related:

csplit - Split a file into context-determined pieces
fmt - Reformat paragraph text 
fold - Wrap input lines to fit in specified width
head - Output the first part of file(s) 
join - Join lines on a common field 
paste - Merge lines of files
split - Split a file into fixed-size pieces
tail - Output the last part of files 
Equivalent Windows command: FOR /F - Conditionally perform a command on items in a text file
Equivalents in NT Batch/Perl Script - CUT Scripts