INFORMATION TECHNOLOGY
Copyright @2020 Julia Williams Matric IT Notes
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,In no particular order:
Freeware 8
FOSS 8
Proprietary software 8
Netbooks 8
ICT 8
USB 9
VGA 9
DVI 9
HDMI 9
DP 9
Thunderbolt 9
Firewire 10
POST 10
UEFI 10
CMOS 10
CPU 11
Multi-core 11
Heat sink 11
GPU 11
RAM 11
Buses 12
Motherboard 12
Firmware 12
Hot swapping/ hot plugging 12
PCI Express 12
SATA 13
2
,Serial Connections 13
NIC 13
System Clock 13
System clock speed 13
GHz 13
Clock multiplier 14
Overclocking 14
Dynamic overclocking 14
Hyperthreading 15
Functions of a server: 15
PAN 15
LAN 15
WAN 15
GAN 15
Fibre Optic Backbone 15
4G (LTE) 16
HSDPA 16
HSUPA 17
USSD 17
RSS Aggregator 17
Evaluation of websites: 17
W3C (WWW Consortium) 17
VOD or AVOD 17
Lossy compression 18
Lossless compression 18
Web 1.0, 2.0, .3.0 18
Client-side scripting 18
3
,Server-side scripting 18
RIA 18
GIGO 18
WEP 19
WPA 19
8 bits = 1 byte 19
UTF - 8 19
Characteristics of a good database: 19
RAD 19
Malware 19
Pharming 20
Phishing 20
Clickbait 20
POP and IMAP 20
SMTP 20
UDP and TCP 21
TCP/IP 21
WebDAV 22
HTTP 22
HTTPS 22
Multi-threading 22
Multi-processing 23
Multitasking 23
Multi-programming 23
Hyperthreading 23
PAAS 24
SAAS 24
4
,IAAS 24
Topology 24
Chipset 25
Bridge 26
Ethernet Switch 26
Ethernet vs WiFi 26
Ethernet 27
POE 27
Router 27
Hub 28
Bridge 28
North Bridge 28
South Bridge 28
DDR 28
DIMM 29
Cache 29
i3, i5, i7 30
TDP (The thermal design power) 31
64 bit vs 32 bit 31
Register 31
UPS 31
Backups 31
NAS 32
SSD and HDD 32
Hybrid drives 34
FAT (File Allocation Table) 34
RAID 34
5
,Virtualisation 35
Client server network 35
Peer to Peer (P2P) 37
BitTorrent 37
Advantages and Disadvantages of Bittorrent 37
Leeching 37
Addons/extensions 38
WAP 38
Hotspot 38
Identity theft 38
Bitcoin 38
Blockchain 39
Botnets 39
DOS 39
Virus vs Worm 39
Keylogger 40
Man in the middle attack 40
SQL injection 40
Zero day exploit 40
Big data 40
Normalisation 41
Data Mining 43
Driver 43
Interpreter 43
API 44
Operating System 44
Compiler 44
6
,Encapsulation 44
Interrupt 44
Software interrupt 44
Gateway 44
FTP 44
VPN 45
VoIP 45
DNS 45
URL 45
IP Addresses 45
IPv4 vs IPv6 45
MAC Address 46
Spoofing 46
Protocol 46
Search engine 46
SEO 46
Semantic search engine 47
IPTV 47
MPEG 47
RFID 47
Rootkit 47
Siphoning 47
Virtual memory 48
Proxy server 48
Firewall 48
Digital signature 49
Encryption 49
7
,Public/ Private Key encryption 49
TLS 50
UML 50
Bounded Media 50
Network vs Internet 51
Activation Code 52
Parallel arrays 52
Downloading vs streaming 52
Cookie 53
Polymorphism 53
Data Structures 54
Trace Table 55
Class Diagrams 56
Terminology list 56
8
,Shareware
Free trial on demo (limited functionality). Shareware is software that is distributed free on a trial
basis with the understanding that the user may need or want to pay for it later. User either has
limited access (some features are locked) or can use the program on a trial basis. Some
software developers offer a shareware version of their program with a built-in expiration date
(after 30 days, the user can no longer get access to the program). EG: A budgeting software
program that only allows you to use three categories instead of having the ability to create a full
budget.
Freeware
Freeware is copyrighted software that is available at no cost for unlimited usage.
EG: Skype, WhatsApp.
FOSS
Free and open-source software (FOSS) is software that can be classified as both free software
and open-source software. Allows users and programmers to edit, modify or reuse the
software's source code. The term "open source" refers to something people can modify and
share because its design is publicly accessible. Source code is released under a license in
which the copyright holder grants users the right to study, change, and distribute the software to
anyone and for any purpose. EG: Linux kernel, GNOME Desktop and Free Berkeley Software
Distribution (FreeBSD).
Proprietary software
Proprietary software is software that is owned by an individual or a company (usually the one
that developed it). There are almost always major restrictions on its use, and its source code is
almost always kept secret. E.g: Microsoft Word, iTunes, Adobe Photoshop, Google Earth.
Netbooks
Smaller, less powerful version of a laptop, normally used for word-processing and
web-browsing.
ICT
Information and communications technology - a system consisting of hardware, software, data
and the people who use it.
It is an extended term for information technology (IT). It is the infrastructure and components
that enable modern computing.
The term is generally accepted to mean all devices, networking components, applications and
systems that combined allow people and organizations (i.e. businesses, nonprofit agencies,
governments and criminal enterprises) to interact in the digital world. ICT encompasses both the
internet-enabled sphere as well as the mobile one powered by wireless networks.
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, USB
A Universal Serial Bus (USB) is a common interface that enables communication between
devices and a host controller such as a PC. It connects peripheral devices such as digital
cameras, mice, keyboards, printers, scanners, media devices, external hard drives and flash
drives.
USB 2.0 = 480mbps
USB 3.0 = 640mbps
VGA
Video Graphics Array is an analog interface between a PC and monitor that was widely used
prior to DVI, HDMI and DisplayPort.
https://www.youtube.com/watch?v=f38sotYHqtA
DVI
Digital Visual Interface is a video display interface.
Almost the same as VGA except physically larger and its advantage is its versatility.
HDMI
High-Definition Multimedia Interface is an audio/video display interface for transferring high
definition video and audio.
DP
DisplayPort is the full package. It is a digital display interface. It has a locking connector. It can
be converted to VGA, DVI and HDMI.
Thunderbolt
A fast connection technology replacing firewire and offering speeds of 10Gbs.
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