Computer Literacy and Safety
Lesson 1 / 15
Pingvi
How a computer works
Processor, memory, disk, operating system; bits and bytes; binary
Chapter 1. Safe in the digital world
15 minutes
Python
4 questions
A computer — whether a phone, a laptop or a server — is made of the same parts:
| Part | Job | Analogy |
|---|---|---|
| Processor (CPU) | runs instructions, computes | the cook |
| Memory (RAM) | what's running right now — fast, but lost when powered off | the kitchen table |
| Disk (SSD/HDD) | stores files permanently | the fridge and shelves |
| Operating system (OS) | runs everything: Windows, Android, Linux, macOS, iOS | the head chef |
When your phone "slows down", usually RAM is full (too many apps open) or the disk is full.
Bits and bytes
Inside a computer everything — text, pictures, music — is made of 0s and 1s. A single 0 or 1 is a bit. 8 bits make a byte.
print(bin(13)) # 13 in binary
print(int("1101", 2)) # from binary to decimal
print(2 ** 8) # how many different values fit in 1 byte
# Output: 0b1101
# Output: 13
# Output: 256
| Unit | Size | Roughly fits |
|---|---|---|
| 1 byte | 8 bits | one Latin letter |
| 1 KB (kilobyte) | 1024 bytes | a short text message |
| 1 MB (megabyte) | 1024 KB | one phone photo (2–5 MB) |
| 1 GB (gigabyte) | 1024 MB | ~1 hour of video |
| 1 TB (terabyte) | 1024 GB | thousands of films |
💡 Internet speed is usually measured in bits (Mbit/s), file size in bytes (MB). 100 Mbit/s is about 12.5 MB a second. That's why "a 100 MB file doesn't download in 1 second on 100-megabit internet".
Practice Python
Turn a byte count into a readable size: under 1024 — bytes, otherwise KB, MB or GB (one decimal place):
500 B
1.5 KB
5.0 MB
2.0 GB
input() data
Write code and press "Run". Loading Python takes a few seconds the first time.
Show solution
def hajm(bayt):
if bayt < 1024:
return f"{bayt} B"
for birlik in ["KB", "MB", "GB"]:
bayt /= 1024
if bayt < 1024 or birlik == "GB":
return f"{bayt:.1f} {birlik}"
for b in [500, 1536, 5_242_880, 2_147_483_648]:
print(hajm(b))