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Lesson 2 Using programming languages to create Web applications
Objective Describe how programming languages are used to develop Web sites.

Using Programming Languages to create Web Apps

Programming languages define the logic computers use to act on data. The data can come from a user or from a database. The logic is the computer's instructions for performing specific operations. Different programming languages support different functions. Programming languages include:
  1. Procedural languages
  2. Object-oriented languages
  3. Data manipulation languages (DMLs)
  4. Scripting languages
  5. Markup languages

Procedural and object-oriented languages

Procedural and object-oriented languages are used for writing programs and application program interfaces (or APIs). An API is a standard interface between an application and other applications or scripts that interact with that application. The API must be written in the language supported by the server, typically C or C++. An API also can be provided by the server vendor. In that case, the API is proprietary and developers would write code that specifically supports the API.
Procedural languages[1], such as C, Visual Basic, and FORTRAN, support logic, math, and animation. Although difficult to learn, object-oriented languages[2], such as C++, Java, and Smalltalk support complex or distributed applications, as well as reusable objects.

Data manipulation languages

Data manipulation languages (DMLs)[3] are used to construct the physical data components of a database and to perform queries and updates. Structured Query Language (SQL) is a common standardized database language. SQL code can be executed on a database server.

Scripting languages

A scripting language is based on a host language that uses a simplified command method with reduced functionality to accomplish basic functions, such as form handling and text processing. For example, VBScript is the scripting language based on VisualBasic, the host language.Easy to learn, scripting languages support control of screen functions and prototyping. Scripting languages include JavaScript, Perl, and JScript.

Markup languages

Markup languages describe how text is to be displayed on a Web page. In a markup language, the instructions are in a set of tags or special characters. Markup languages do not provide interactive functionality. They serve as containers for text and graphics.
SGML, HTML, DHTML, and XML are multiplatform, standardized markup languages that display complex hypertext and can be read by humans.
In the next lesson, you will learn about the purpose of client-side scripts and applets.

[1]Procedural language: Programming language used for writing application program interfaces. Procedural languages, such as C, VB, and FORTRAN support logic, math, and animation.
[2]Object-oriented language: Programming language, such as C++ and Java, used to support complex or distributed applications and reusable objects.
[3]Data manipulation language (DML): Programming language used to construct the physical data components of a database and to perform queries and updates.