1.3 Illustrate the basics of computing and processing
📘CompTIA ITF+ (FC0-U61)
What Is Input?
Input is any data or instruction that is sent into a computer system so it can be processed.
A computer cannot work on its own. It must receive input first.
After receiving input, the computer processes it and then produces output.
Input → Processing → Output
This is a core concept tested in the CompTIA ITF+ exam.
Types of Input
Input can come in many forms, but all of them provide data to the system.
Common Input Data Types
- Text
- Numbers
- Images
- Audio
- Video
- Commands or instructions
Input Devices (IT-Focused)
An input device is hardware that allows users or systems to send data into a computer.
Keyboard
- Used to enter text, numbers, and commands
- Common in operating systems, servers, and terminals
Mouse / Touchpad
- Used to select, click, drag, and interact with software interfaces
Touchscreen
- Allows direct input by touching the display
- Common in tablets, kiosks, and mobile devices
Scanner
- Converts paper documents into digital format
- Used in offices to store files electronically
Microphone
- Converts sound into digital data
- Used for voice commands, online meetings, and voice recognition systems
Camera / Webcam
- Captures images or video as input
- Used in video conferencing and security systems
System-Based Input (Important for Exam)
Not all input comes directly from a user.
File Input
- Data read from a file stored on a disk
- Example: A program reading a configuration file
Network Input
- Data received from another system over a network
- Example: Data sent from a server to a client
Sensor Input
- Input from sensors connected to systems
- Example: Temperature or motion sensors sending data to software
Input in an IT Environment
In real IT systems, input is often:
- Automated
- Continuous
- Generated by other systems
Examples:
- Login credentials entered into an operating system
- Data submitted through a web form
- Commands entered into a command-line interface
- Data received from APIs
- Logs collected from network devices
Input and Data Processing
Once input is received:
- The CPU processes it
- The system may store it in memory or storage
- The system produces output
If input is incorrect, the output will also be incorrect.
This concept is known as:
GIGO (Garbage In, Garbage Out)
Meaning:
- Poor or incorrect input results in poor output
This is an important exam concept.
Input Validation (Exam Concept)
Input validation ensures that data entered into a system is:
- Correct
- Complete
- In the proper format
Examples:
- Accepting only numbers where numbers are required
- Rejecting empty fields
- Checking username and password formats
Why input validation is important:
- Prevents errors
- Improves system reliability
- Helps with security
Input vs Output (Comparison)
| Input | Output |
|---|---|
| Data entered into the system | Data produced by the system |
| Comes before processing | Comes after processing |
| Sent to the computer | Sent from the computer |
Understanding this difference is essential for ITF+.
Role of Input in the Computing Cycle
The basic computing cycle is:
- Input – Data enters the system
- Processing – CPU works on the data
- Output – Results are shown
- Storage – Data is saved for later use
Input is always the first step.
Key Exam Points to Remember
- Input is any data or instruction sent to a computer
- Input devices allow interaction with systems
- Input can come from users, files, networks, or sensors
- Incorrect input leads to incorrect output (GIGO)
- Input validation checks data accuracy
- Input is the starting point of computing and processing
Simple Summary
- Computers need input to work
- Input can be manual or automated
- Input devices help send data to systems
- Input affects the quality of output
- Understanding input is essential for IT fundamentals
