CS 0478 Chapter 4: The Hardware & Software Audit Swasti’s ”1st Position” Series
Chapter 4: Hardware & Software
The Complete Protocol, Systems, & Languages Lockdown
”The intersection of connectivity and control.” ����
1. Internet Communication Protocols
A. Data Packets (The Unit of Transfer)
Data is broken into Packets for transmission.
⋄Packet Header: Contains sender/receiver IP, and the Packet Number (to reassemble them in
order).
⋄Payload: The actual data being sent.
⋄Trailer: Contains the Checksum (error detection) and an ”end-of-packet” marker.
⋄Packet Switching: Packets take different routes to reach the destination; they are reassembled using
the numbers in the header.
B. IP vs. MAC Addresses (Identity)
Feature MAC Address IP Address
Full Name Media Access Control Internet Protocol
Nature Physical address (Perma-
nent).
Logical address (Tempo-
rary).
Assignment Set by the manufacturer
(NIC).
Set by the network/ISP.
C. Web Protocols DNS
•HTTPS: Secure web protocol using Encryption.
•DNS (Domain Name System): Translates a URL (e.g. google.com) into an IP Address.
•Cookies: Small text files that store user preferences. They are not malware.
2. The Operating System (OS) & Utilities
A. OS Management Tasks
The OS manages the hardware so application software can run.
•Interrupt Handling: Responding to signals (Interrupts) that stop the CPU’s current task to deal
with an event (e.g., mouse click, hardware failure).
•Memory Management: Allocating RAM to processes.
•Security: Managing users and file permissions.
B. Utility Software
•Defragmentation: Reorganizes files on a HDD into contiguous sectors to speed up access.
•Compression: Reduces file size to save storage.
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