Essential Computer Science Concepts and IT Definitions
System Fundamentals
A system is a set of interrelated parts working together to achieve a common goal.
System Components
- Environment
- Inputs
- Process
- Outputs
Information Systems
An Information System (IS) is a set of elements and procedures designed to improve data processing and elaborate reports, facilitating decision-making to achieve beneficial goals.
Data Processing
Data Processing is a series of elementary operations performed on data to produce results.
Process Flow: Reception → Storage → Processing → Output of Results
Informatics and Computer Science
Informatics is the science that studies the automatic and rational treatment of information.
It develops new machines, methods, and applications, improving and streamlining the transformation of Data into Information.
Data vs. Information
- Fact
- An item that serves as a starting point.
- Information
- The outcome of data treatment.
Computer Hardware Basics
What is a Computer?
A computer is a machine capable of receiving information, storing it, and performing calculations.
Hardware Components
Hardware refers to the physical components of a personal computer (PC).
Central Processing Unit (CPU)
The CPU (Central Processing Unit) comprises the Control Unit, Arithmetic Logic Unit (ALU), main memory, registers, and buses.
- Stores data, instructions, and results.
- Interprets and executes instructions.
- Moves data and instructions.
Random Access Memory (RAM)
RAM (Random Access Memory) is volatile memory that allows both reading and writing. It requires continuous power and is composed of bits.
Bits: The simplest unit of information in a binary system.
Computer Peripherals
Peripherals are devices that connect to the CPU to facilitate communication between the computer and the external environment.
- Input Peripherals
- Used to enter data (e.g., Keyboard, Mouse).
- Output Peripherals
- Used to display results (e.g., Display/Monitor).
Software Translators
Software translators convert programming code into executable instructions.
- Interpreter
- Translates code line by line as it reads, converting it directly into actions. It works on any platform but requires its interpreter to run.
- Compiler
- Translates the entire program into another language (machine code) before execution. The compiled program runs independently. It typically works only on the platform it was compiled for, but the compiled file can be distributed. Compilers generally offer faster execution speed.
Storage Devices: Hard Drive
A Hard Drive stores information using a digital magnetic recording system.
Hard Drive Components
- Platter
- Each of the disks inside the hard drive.
- Track
- A concentric circle on a platter’s surface.
- Cylinder
- A group of multiple tracks that are vertically aligned across all platters.
- Sector
- Each of the divisions of a track.
Types of Computers
- Analog Computers
- Operate using electronic circuits that reproduce data through physical quantities, typically solving specific problems.
- Digital Computers
- Process electronic signals where values are represented as 0s and 1s (binary).
Software and Programs
What is a Program?
A program is a coded set of instructions.
Operating System (OS)
An Operating System (OS) is a program that facilitates communication between the user and the PC.
- Controls system resources.
- Provides a platform for other programs.
- Manages and allocates hardware resources.
Database Fundamentals
Database Definition
A database is a structured collection of symbols, letters, and numbers that hold meaning and become useful information.
Database Management System (DBMS)
A Database Management System (DBMS) is a collection of interrelated data and a set of programs used to access and manage data in an orderly, easy, and clear manner.
Key Features of DBMS
- Abstraction of Information: Hides complex details.
- Data Independence: Data does not depend on the application program.
- Security: Provides control over data security.
- Reduction of Redundancy: Minimizes data duplication across databases.
- Consistency: Ensures data adheres to defined programming conditions.
- Integrity: Guarantees data is entered correctly.
- Backup and Recovery: Mechanisms for data protection and restoration.
- Concurrency Control: Manages simultaneous access to information.
Examples: PostgreSQL, Firebird.
Computer Networking Essentials
What is a Network?
A network is a collection of autonomous, interconnected personal computers (PCs).
Common connection methods include:
- Via cable (e.g., Ethernet)
- Via modem (e.g., ADSL)
- Via wireless (e.g., Wi-Fi)
Benefits include: Sharing resources, data backup, information sharing, and enabling communications.
Network Topology
Network Topology refers to the arrangement or relationship between computers and devices in a network.
Common Network Topologies
- Mesh Topology: Each device is connected point-to-point to every other device.
- Star Topology: All devices are connected to a central hub or switch.
- Tree Topology: Combines characteristics of bus and star topologies, with PCs concentrating at major nodes.
- Bus Topology: A single cable connects all devices.
- Ring Topology: Each PC is connected to exactly two other PCs, forming a ring.
Types of Networks
- LAN (Local Area Network)
- Connects devices within a limited area, such as a single building.
- WAN (Wide Area Network)
- Interconnects multiple LANs over a large geographical area.
- MAN (Metropolitan Area Network)
- Covers a city or a large campus.
- VPN (Virtual Private Network)
- Extends a private network across a public network infrastructure, enabling secure communication.
Internet and Intranet
The Internet is a global network of interconnected computer networks.
An Intranet is a private network accessible only to an organization’s members.
Network Protocols
A protocol is a set of rules governing data communication. Key functions include:
- Mechanism to identify sender and recipient.
- Control of errors in data packets.
- Control of message order.
- Routing directions.
Examples: IPX, TCP/IP.
TCP/IP (Transmission Control Protocol/Internet Protocol): A fundamental suite of protocols for networking, responsible for establishing and maintaining connections across multiple subnets.