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Network devices are hardware components that connect computers and manage data traffic between them. Each device works at a different layer of the network.

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🧩 1️⃣ Modem

Full form: Modulator–Demodulator

🔹 Purpose:

• Connects your home/office network to the Internet Service Provider (ISP)

• Converts digital data ↔ analog signals

🔹 Example:

Fiber or broadband modem provided by your ISP.

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🛜 2️⃣ Router

🔹 Purpose:

• Connects multiple devices to the internet

• Assigns IP addresses

• Directs traffic between networks

🔹 Works at:

• Network Layer (Layer 3) of OSI model

🔹 Real-world example:

Home Wi-Fi router

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🔌 3️⃣ Switch

🔹 Purpose:

• Connects devices within the same network

• Sends data only to the intended device

🔹 Works at:

• Data Link Layer (Layer 2)

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🔄 4️⃣ Hub (Older Technology)

🔹 Purpose:

• Connects multiple devices

• Sends data to all connected devices

🔹 Problem:

• Causes network congestion

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📡 5️⃣ Access Point (AP)

🔹 Purpose:

• Extends wireless coverage

• Converts wired network → wireless signal

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🛡 6️⃣ Firewall

🔹 Purpose:

• Protects network from unauthorized access

• Filters incoming/outgoing traffic