Unit 3: Internet & Networking
Chapter 13: Database, DBMS & SQL
Hinglish Explanation: Database data ko structured form me store karta hai. DBMS data ko insert, update, delete aur retrieve karne ke tools deta hai.
- Table consists of rows/records and columns/fields.
- Primary key: uniquely identifies a row.
- Foreign key: creates a relationship with another table.
- SQL: is used to interact with relational databases. CRUD = Create, Read, Update, Delete.
Chapter 14: Internet & World Wide Web
- Internet: A global network of interconnected networks.
- WWW: Linked web resources that use the Internet to be accessed.
- URL: identifies the location of a web resource.
- HTTPS: adds encryption through TLS.
How a Web Request Works
Chapter 16: Networking Fundamentals
- PAN: Personal area network (around a person).
- LAN: Covers a small local area (Building/campus).
- MAN: City/metropolitan area.
- WAN: Covers large geographical areas (e.g., The Internet).
- Bandwidth: data-carrying capacity; latency: delay.
Chapter 17 & 18: Network Topologies & Devices
| Topology | Key feature |
|---|---|
| Bus | Shared backbone |
| Star | Central device |
| Ring | Loop |
| Mesh | Multiple paths |
Devices
- Hub: Broadcasts incoming frames to all ports.
- Switch: Forwards frames using MAC addresses.
- Router: Forwards packets between networks using IP information.
- Modem: Converts/mediates signals for Internet access technologies.
Chapter 19: IP Address, MAC, DNS & DHCP
English Definition: An IP address identifies a network interface for communication at the Internet Protocol layer; a MAC address identifies a network interface at the link layer.
- IPv4: uses 32-bit addresses; IPv6: uses 128-bit addresses.
- DNS: translates domain names to IP addresses.
- DHCP: dynamically assigns network configuration such as IP address.
- MAC address: is commonly represented in hexadecimal.
Chapter 20 & 21: OSI, TCP/IP & Protocols
OSI 7 Layers Trick (Top to Bottom): Application, Presentation, Session, Transport, Network, Data Link, Physical.
| Protocol | Use |
|---|---|
| HTTP/HTTPS | Web (Application layer) |
| FTP | File transfer |
| SMTP | Send email |
| POP3/IMAP | Receive/sync email |
| TCP | Connection-oriented and reliable |
| UDP | Connectionless with lower overhead |
📝 SSC Practice MCQs (Unit 3)
SSC CGL
Q1. Which device connects different networks?
Answer: B. Router
Solution: A router connects different networks and forwards data packets using IP addresses.
Solution: A router connects different networks and forwards data packets using IP addresses.
SSC CHSL
Q2. What does DNS primarily do?
Answer: B. Resolve domain names
Solution: DNS (Domain Name System) acts like a phonebook, translating human-readable names (like google.com) to IP addresses.
Solution: DNS (Domain Name System) acts like a phonebook, translating human-readable names (like google.com) to IP addresses.
SSC MTS
Q3. Which protocol is used for web browsing?
Answer: A. HTTP/HTTPS
Solution: HTTP and HTTPS are the standard protocols for accessing and displaying web resources.
Solution: HTTP and HTTPS are the standard protocols for accessing and displaying web resources.
SSC CPO
Q4. Which OSI layer is associated with IP?
Answer: C. Network
Solution: The Network Layer (Layer 3) handles IP addressing and routing.
Solution: The Network Layer (Layer 3) handles IP addressing and routing.
SSC Selection Post
Q5. Which topology uses a central device?
Answer: C. Star
Solution: Star topology connects all devices to a central hub or switch.
Solution: Star topology connects all devices to a central hub or switch.