Structured Programming Languages

Programming languages are used to describe algorithms, i.e. sequences of steps that lead to the solution of problems. Programming languages are broadly classified into two groups: low-level languages and high-level languages. Low-level languages are close to machine languages. They demonstrate a strong correspondence between the operations implemented by the language and the operations implemented by the underlying hardware. High-level languages in contrast are closer to human languages. Each statement in a high-level language will be equivalent to many statements of a low-level language. The key advantage offered by high-level languages is therefore abstraction. As the level of abstraction increases the programmer needs to be less and less concerned about the hardware on which a program runs and more and more concerned with the problems of the application. Hence, the trend has been to build more and more abstraction into programming languages.