A connection is a link between two or more devices that allows them to communicate, share data, or access resources. In simple words: It’s how devices “talk” to each other. A link between two or more devices that allows them to communicate and exchange data.

1. What is a connection in a Computer or Computer Network
A connection is a link between two or more devices that allows them to
communicate, share data, or access resources.
In simple words: It’s how devices “talk” to each other.
A link between two or more devices that allows them to communicate and
exchange data.
Examples of Connection
1.Wired Connection
1. Using cables like Ethernet/LAN cable to connect a computer to a router.
2. Example: Your PC is connected to a home router via a LAN cable to access the Internet.
2.Wireless Connection
1. Using Wi-Fi, Bluetooth, or Infrared to connect devices without cables.
2. Example: A Smartphone connected to a Wi-Fi network to browse the Internet.
3.Internet Connection
1. A link that allows a device to access the Internet.
2. Example: Fiber, DSL, or mobile data connection.

2. Key Point
• A connection enables communication.
• It can be wired (Ethernet, USB) or wireless (Wi-Fi, Bluetooth,
Infrared).

3. What are the three types of
connections?
These are the three basic data communication connection
types:
A. Wired Connection
Uses physical cables to transmit data.
Examples:
• Ethernet (LAN cable)
• Fiber-optic cable
• Coaxial cable

4. Cont…
B. Wireless Connection
Transfers data without physical cables.
Examples:
• Wi-Fi
• Bluetooth
• Infrared (IR)
• Satellite communication

5. Cont…
C. Mobile (Cellular) Connection
Uses telecommunication towers and SIM-based networks.
Examples:
• 3G
• 4G LTE
• 5G
• GSM(Global System for Mobile
Communications)/UMTS(Universal Mobile
Telecommunications System) networks

6. Cont…
From the above categories, the internet can be provided
through all three types:
• Wired internet Fiber, DSL, Cable internet
→
• Wireless internet Wi-Fi, Satellite internet
→
• Mobile internet 3G/4G/5G data
→
So, the Internet is not a single category—it can use wired,
wireless, or mobile connections depending on the
technology.

7. 3. What are the types of internet connections?
Here are the commonly used internet connection types:
A. Wired Internet Types
• Fiber-optic internet (fastest)
• Cable internet
• DSL (Digital Subscriber Line)
• Ethernet LAN (for local networks)
B. Wireless Internet Types
• Wi-Fi (local wireless access)
• Satellite internet
• Fixed wireless broadband
C. Mobile Internet Types
• 3G
• 4G LTE
• 5G
• Mobile hotspot / Tethering

8. 1. How does Wi-Fi work?
Wi-Fi is a wireless networking technology that uses radio
waves to send and receive data between devices and a router.
How it works (simple explanation):
1.Your router receives internet from your ISP (fiber, DSL, cable, or
mobile).
2.The router converts this internet signal into Wi-Fi radio waves.
3.Your phone/laptop connects to those radio waves using a Wi-Fi
antenna.
4.The router sends your data to the ISP then to the internet
→ →
and back to your device.
✔ Wi-Fi = local wireless network signal
✔ Wi-Fi is NOT the internet
✔ Wi-Fi only distributes the internet inside your
home/office

9. Does Wi-Fi need a tower?
No — Wi-Fi does NOT use ISP towers.
Wi-Fi uses a router, not a tower.
Important distinction:
• Wi-Fi router Creates a local wireless signal in your home
→
• ISP tower Used only for
→ mobile data (4G/5G) or fixed
wireless broadband
When a Wi-Fi router does need a tower:
Only if the router gets internet through a SIM card using
mobile data (4G/5G router).
Then the internet comes from the tower, but the Wi-Fi signal
is still local.

10. 3. What is the difference between DSL, Cable, and LAN/Ethernet?
A. DSL (Digital Subscriber Line)
• Uses telephone lines (copper twisted-pair).
• The Internet runs simultaneously with telephone service.
• Speeds: slow to medium.
B. Cable Internet
• Uses coaxial TV cables.
• Faster than DSL.
• More stable.
C. LAN / Ethernet
• It is a local wired network connection, usually inside a home or office.
• Uses Ethernet cables (Cat5/6/7).
• Connects devices to the router (PC router).
→
✔ DSL and Cable = Internet connection types
✔ Ethernet = local network connection type

11. DSL has several types. The most common are:
DSL Types
1.ADSL – Asymmetric DSL (download faster than upload)
2.SDSL – Symmetric DSL (equal upload and download)
3.VDSL – Very High-Speed DSL (faster than ADSL)
4.VDSL2 – New version, much higher speed
5.HDSL – High-bit-rate DSL
6.RADSL – Rate-adaptive DSL
7.IDSL – ISDN DSL (rare, old)

12. Technology Category
DSL Wired connection
Cable internet Wired connection
Ethernet (LAN) Wired connection
Fiber Wired connection

13. Wireless examples:
Wi-Fi, Bluetooth, Satellite
Mobile examples:
3G, 4G, 5G
For LAN / Ethernet and DSL (Twisted pair copper phone line):
Cable type is the same, but usage is different
• LAN / Ethernet cable (Cat5/6/7):
• Purpose: Local area network (LAN)
• Connects devices to a router or switch inside a home, office, or building.
• Carries data within your local network; it does not directly provide internet from
your ISP.
• DSL (Twisted pair copper phone line):
• Purpose: Internet access
• Connects your home to the ISP over the telephone line.
• The ISP’s DSLAM (Digital Subscriber Line Access Multiplexer)equipment converts it
to internet traffic.
 Both use copper wires, but one is for local network distribution, and the
other is for external internet access.

14. Why is LAN cable not categorized as an Internet
connection
• Internet connection types are defined by how you get
internet from the ISP: DSL, Cable, Fiber, Mobile, Satellite.
• LAN/Ethernet is just the “last mile” inside your building,
carrying the ISP signal to your device.
• Think of it like this:
• Internet connection type = the source of the internet.
• LAN cable = how you distribute the internet locally.

15. DSL (Digital Subscriber Line) uses telephone lines, which are
made of twisted-pair copper cables.
1.Twisted-Pair Copper Cable
1.Two insulated copper wires twisted together to reduce interference.
2.Same type of cable used for traditional telephone lines.
2.Variants / Categories:
1.Cat3 – Often used for older ADSL connections.
2.Cat5 / Cat5e / Cat6 – Can be used for DSL modems and internal
wiring for better performance.
3.Connections in DSL setup:
1.From ISP to home: Twisted-pair copper telephone line
2.Inside home (modem to computer/router): Usually Ethernet cable
(Cat5/6)
 Key point: DSL itself runs over twisted-pair copper, but
inside your house, you usually use Ethernet cables to connect
devices

16. Feature DSL Twisted-Pair Cable Ethernet Cable
(Cat5/5e/6/6a/7)
Purpose Carries DSL signal from ISP to
home
Connects devices in a LAN
(local network)
Wire structure Usually, 1 or 2 pairs of copper
wires
Usually 4 pairs (8 wires) of
copper wires
Twisting Twists per pair may vary; less
standardized
Twists per pair are
standardized for noise
reduction at higher
frequencies
Connector RJ-11 (telephone jack) RJ-45 (Ethernet jack)
Frequency Up to a few MHz Up to 600 MHz (Cat6) or more
(higher categories)
Distance & Speed Works up to ~5 km, speeds up
to ~100 Mbps (ADSL/VDSL)
Shorter distances (100 m for
Cat5e/Cat6), speeds up to 10
Gbps+
Summary:
•DSL cable = telephone line, simpler, fewer pairs, lower frequency.
•Ethernet cable = network cable, more pairs, higher frequency, standardized for LAN.

17. What is a Dial-Up Connection?
• Dial-up is an older type of internet connection.
• It uses a standard telephone line (twisted-pair copper cable)
to connect your computer to the ISP.
• Connection is made via a modem that dials the ISP’s phone
number.
• Internet speed: very slow, usually up to 56 kbps.

18. What is a Telephone Network?
A telephone network is a large communication system that allows people
to make voice calls to each other over long distances.
It connects telephones in homes, offices, and mobile devices through a
combination of wired and wireless technologies.
What is VoIP?
VoIP = Voice over Internet Protocol
It is a technology/method of making voice calls over the internet instead
of traditional telephone lines.
An IP Phone is a device (hardware telephone) designed to make VoIP calls.
So VoIP is a service or technology, not a device.
Examples of VoIP services:
• WhatsApp call
• Skype
• Zoom
• Google Meet
• SIP-based office phone systems

19. Thank You!!