Programming Language

Programming Languages

A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely.

Now that we know that what programming languages mean let us know how many programming languages exist if you could check the below link on google you would fine a list of Programming Languages.
The aim of this list of programming languages is to include all notable programming languages in existence, both those in current use and historical ones, in alphabetical order, except for dialects of BASIC and esoteric programming languages.
Note: Dialects of BASIC have been moved to the separate List of BASIC dialects.
Note: This page does not list esoteric programming languages.
http://en.wikipedia.org/wiki/List_of_programming_languages

Programming languages share properties with natural languages related to their purpose as vehicles for communication, having a syntactic form separate from its semantics, and showing language families of related languages branching one from another.[32][33] But as artificial constructs, they also differ in fundamental ways from languages that have evolved through usage. A significant difference is that a programming language can be fully described and studied in its entirety, since it has a precise and finite definition.[34] By contrast, natural languages have changing meanings given by their users in different communities. While constructed languages are also artificial languages designed from the ground up with a specific purpose, they lack the precise and complete semantic definition that a programming language has.

Many programming languages have been designed from scratch, altered to meet new needs, and combined with other languages. Many have eventually fallen into disuse. Although there have been attempts to design one "universal" programming language that serves all purposes, all of them have failed to be generally accepted as filling this role.[35] The need for diverse programming languages arises from the diversity of contexts in which languages are used:
Programs range from tiny scripts written by individual hobbyists to huge systems written by hundreds of programmers.
Programmers range in expertise from novices who need simplicity above all else, to experts who may be comfortable with considerable complexity.

Programs must balance speed, size, and simplicity on systems ranging from microcontrollers to supercomputers.
Programs may be written once and not change for generations, or they may undergo continual modification.
Finally, programmers may simply differ in their tastes: they may be accustomed to discussing problems and expressing them in a particular language.

All programming languages have some primitive building blocks for the description of data and the processes or transformations applied to them (like the addition of two numbers or the selection of an item from a collection). These primitives are defined by syntactic and semantic rules which describe their structure and meaning respectively.
i)Syntax
ii)Semantics
a)Static Semantics
b)Dynamic Semantics
c)Type system-they are of three types
-Typed versus untyped languages
-Static versus dynamic typing
-Weak and Strong Typing
iii)Standard library and runtime system.

Programming Languages that stand-out

Among thousands, 10 programming languages stand out for their job marketability and wide use. If you're looking to boost your career or learn something new, start here.

Knowing a handful of programming languages is seen by many as a harbor in a job market storm, solid skills that will be marketable as long as the languages are. Yet, there is beauty in numbers. While there may be developers who have had riches heaped on them by knowing the right programming language at the right time in the right place, most longtime coders will tell you that periodically learning a new language is an essential part of being a good and successful Web developer.

Programming languages one needs to learn

1)PHP
2)C#
3)Java
4)C Language
5)Python
6)Perl
7)Javascript
8)Visual Basics
9)C++
10)Objective-C

Q)Programming Languages Design and Implementation?

Q)Programming languages Fundamentals/Concepts?

Reference

Wikipedia
Check the below books
Programming Language-Design and Implementation(Author-Terrence Wendall Pratt, Marvin V. Zelkowitz)
Concepts of Programming Language(Author-Sebesta)
The Study of programming languages(Author-Ryan.D,Stansifer)