Introduction to IT

What Is Information Technology?

Information Technology (IT) is the use of digital technology - computers, networks, and software - to store, process, and communicate information. IT support is the role responsible for keeping these systems running and helping people use them effectively.

History of Computing

Computing began with punch cards - holes in cards represented binary data for early machines
Cryptography during WWII (e.g., Enigma decryption) drove major advances in computational design
Early computers filled entire rooms; today a smartphone has billions of times more processing power
The rise of open-source software (anyone can view, modify, share code) fundamentally shaped modern computing

Digital Logic - Binary

Computers communicate in binary - a base-2 number system using only 1s and 0s.

Term	Definition
Bit	A single binary digit - 0 or 1
Byte	A group of 8 bits
Character	One byte can store one character (256 possible values with 8 bits)

Why Binary?

Transistors - the fundamental building blocks of CPUs - have two states: on (1) or off (0). Binary maps directly to this physical reality.

Character Encoding

Character encoding assigns binary values to human-readable characters:

ASCII: Maps 128 characters (English letters, digits, symbols) to binary values
UTF-8: Extends ASCII, represents characters using 1–4 bytes - supports emoji, international scripts

Example: the binary value 01100001 = decimal 97 = ASCII character a

Binary → Decimal Conversion

Each bit position represents a power of 2:

Bit position:  7    6    5    4    3    2    1    0
Power of 2:   128   64   32   16    8    4    2    1

Binary: 01100001
Result: 0+64+32+0+0+0+0+1 = 97

Computer Architecture Layers

Modern computing is built on abstraction - each layer hides complexity from the layer above it.

Layer	Description
Hardware	Physical components - CPU, RAM, storage, motherboard
Operating System	Manages hardware and provides services to software
Software	Applications that run on the OS and solve user problems
User	The human interacting with the system

Logic Gates

Logic gates are the building blocks of digital circuits. They take binary inputs and produce binary outputs based on logical rules:

Gate	Operation
AND	Output is 1 only if ALL inputs are 1
OR	Output is 1 if ANY input is 1
NOT	Flips the input (0 → 1, 1 → 0)
NAND / NOR / XOR	Combinations of the above

Billions of logic gates make up a modern CPU.

The Role of IT Support

IT Support specialists:

Fix technology - hardware, software, networking issues
Improve how people use technology - training, documentation, tool selection
Keep systems running - monitoring, updates, security, backups
Bridge technical and non-technical worlds - translating between user needs and technical solutions

Key skill: troubleshooting - systematic problem-solving under pressure. A good IT specialist asks questions before reaching for solutions.