The language considered the "foundation stone" for teaching languages like FORTRAN, ALGOL, PASCAL, and many others is ALGOL (Algorithmic Language). ALGOL was a significant early programming language that influenced the design of subsequent programming languages, providing important concepts and structures used in the development of languages like FORTRAN, PASCAL, and C. While BASIC is also a widely used beginner-friendly programming language, ALGOL had a substantial impact on the development of programming language theory and design.

FORTRAN (short for "Formula Translation") is a high-level programming language that is particularly well-suited for scientific and engineering applications. It was developed for numeric and scientific computing and is widely used in fields such as physics, engineering, mathematics, and other scientific disciplines. FORTRAN allows for efficient processing of mathematical and scientific computations, making it a popular choice for complex scientific simulations, mathematical modeling, and computational research.

COBOL (Common Business Oriented Language) is a high-level programming language primarily used for business, finance, and administrative systems within companies and governments. It is particularly useful for handling large-scale, data-centric applications in areas such as accounting, payroll, inventory management, and other business-related tasks. COBOL is known for its readability and ease of use, making it suitable for professionals working on applications that require extensive data processing and business logic. Despite being an older language, COBOL continues to be used in many legacy systems, especially in industries where stability and reliability are paramount.

Parsing, in high-level language transformation, is the analysis of code syntax using formal grammar rules. It checks for errors and creates a parse tree representing the code's structure. This tree guides the generation of machine code or program execution, ensuring correct interpretation and execution of the source code.

An array is used to store values in memory. Arrays allow you to store multiple values of the same data type under a single variable name, making it easier to manage and manipulate data in programming. Arrays are commonly used in various programming languages for tasks such as storing collections of data, performing calculations on large sets of values, and iterating through elements to process them. Arrays are not used for deleting values in memory or for output; their primary purpose is to store and organize data.

Operators are symbols that we use when performing operations on one or more operands. The primary types of operators in C are arithmetic, logical, relational, conditional, bitwise, and assignment.

The key difference lies in when the loop condition is checked. In the while loop, the condition is checked before the first iteration, potentially resulting in zero iterations. In the do-while loop, the condition is checked after the first iteration, ensuring that the loop body is executed at least once.