Computer Science Fundamentals and Programming Basics

Computer Science Fundamentals

Informatics is the science or technical study of technology that enables the automatic processing of information using electronic devices and computer systems.

Hardware and Software

• Hardware: All the physical parts that compose a computer.
• Software: A set of programs that execute tasks using the electrical circuits of the computer.

Software Types:

• System Software
• Software Development
• Application Software

Numbering Systems

• Decimal System: Each figure has a weight where its value depends on its location.
• Binary System: The most elementary coding system, using only "0" and "1". This coding avoids confusion in electronic systems because they identify only two possible states.

Bits and Bytes

A bit is an electronic signal that can be either on (1) or off (0). It is the smallest unit of information used by a computer. A byte is composed of 8 bits.

Programming Languages

• Low-Level Languages: Tied more directly to the design of the computer. They are specific to each machine (e.g., assembly language).
• High-Level Languages: Closer to the language of the programmer, and programs can be made to run on different machines (e.g., Basic, Pascal, C, Visual Basic, Java, PHP).

Compilers and Interpreters

Symbolic Language (Source Program) -> Translation -> Machine Language Program (Object Program)

• Compiler: A program that translates a program written in a symbolic language (source program) into machine code (object program). The object program obtained from the compilation is the software that runs the machine.
• Interpreter: A program that translates the source program while the machine is running.

Pseudocode

Pseudocode is used to develop a program that is not specific to any particular language, but which facilitates its subsequent implementation in any of them. Knowing the meaning of each symbol used in flowcharts, creating pseudocode is quite simple. For example:

Program Start
  Ask for dividend
  Ask for divisor
  If divisor = 0 Then
    Show Error
    Go back and ask for divisor
  Else
    Calculate quotient
    Show quotient
  End If
Program End

Constants and Variables

• Constant: Takes an initial value that cannot be changed during program execution. An example is a constant named PI that contains the value 3.14.
• Variable: An identifier used for both reading and writing operations in memory. This means the value of a variable can change at any time during program execution.

Flow Control Structures

A program must be able to make decisions based on certain variables. To achieve this, two basic structures are needed in programming: loops and conditionals.