define programming language

I find Wikipedia a useful source of information. Here is
the Wikipedia explanation.

A programming
language is an artificial href="http://en.wikipedia.org/wiki/Language">language designed to
communicate href="http://en.wikipedia.org/wiki/Machine_instruction">instructions to a
machine,
particularly a href="http://en.wikipedia.org/wiki/Computer">computer. Programming
languages can be used to create href="http://en.wikipedia.org/wiki/Program_(machine)">programs that control
the behavior of a machine and/or to express href="http://en.wikipedia.org/wiki/Algorithm">algorithms
precisely.

The earliest programming languages predate the
href="http://en.wikipedia.org/wiki/History_of_computing_hardware">invention of the
computer, and were used to direct the behavior of machines such as title="Jacquard loom" href="http://en.wikipedia.org/wiki/Jacquard_loom">Jacquard
looms and href="http://en.wikipedia.org/wiki/Player_piano">player pianos. Thousands
of different programming languages have been created, mainly in the computer field, with
many more being created every year. Most programming languages describe computation in
an href="http://en.wikipedia.org/wiki/Imperative_programming">imperative
style, i.e., as a sequence of commands, although some languages, such as those that
support href="http://en.wikipedia.org/wiki/Functional_programming">functional
programming or href="http://en.wikipedia.org/wiki/Logic_programming">logic programming,
use alternative forms of description.

A programming
language is usually split into the two components of href="http://en.wikipedia.org/wiki/Syntax">syntax (form) and title="Semantics" href="http://en.wikipedia.org/wiki/Semantics">semantics
(meaning). Some languages are defined by a specification document (for example, the
href="http://en.wikipedia.org/wiki/C_(programming_language)">C programming
language is specified by an href="http://en.wikipedia.org/wiki/International_Organization_for_Standardization">ISO
Standard), while other languages, such as href="http://en.wikipedia.org/wiki/Perl">Perl, have a dominant title="Programming language implementation"
href="http://en.wikipedia.org/wiki/Programming_language_implementation">implementation
that is used as a reference.

If you invent a ‘Toaster’ and
wanted to program the same think of the syntax and semantics you could
use.

Select – Choose Type of
Bread

Pre Warm [period] – duration of pre-warm
time

…. Similarly for toasting and cool down
tim

…. Add a variety of alarms
etc.

…. Test Moisture Level
etc.

Hopefully you get the idea..