| Concept | What It Is | Example | Analogy |
|---|---|---|---|
| URL | Uniform Resource Locator: The complete web address specifying protocol, host, port, directory path, and query parameters. | https://adwitiya.com:443/dcet?batch=2027#enroll | Complete postal mailing address including country, PIN code, and flat number. |
| Domain Name | Human-readable alphanumeric identifier registered with ICANN/DNS representing an entity or organization on the internet. | adwitiyaacademyoflearning.com | A person's official legal name. |
| DNS | Domain Name System: Distributed, hierarchical, global database that translates human domain names into numerical IP addresses. | google.com ➔ 142.250.192.46 | Global telephone directory / contacts app. |
| IP Address | Internet Protocol Address: Unique numerical identifier assigned to every device connected to a computer network for routing packets. | 192.168.1.1 (IPv4) or 2001:db8::1 (IPv6) | GPS coordinates / exact physical location. |
| Feature | IPv4 (Internet Protocol v4) | IPv6 (Internet Protocol v6) |
|---|---|---|
| Address Length | 32 bits (4 octets / 4 bytes) | 128 bits (16 octets / 16 bytes) |
| Notation Format | Dotted-decimal (e.g. 192.168.1.100) | Colon-separated hexadecimal (e.g. 2001:0db8:85a3::8a2e:0370:7334) |
| Total Addresses | ~4.29 Billion ($2^{32}$ addresses) — Exhausted! | ~340 Undecillion ($2^{128}$ addresses) — Virtually infinite! |
| Header Size | Variable (20 to 60 bytes with options) | Fixed 40 bytes (faster router processing) |
| Configuration | Manual or DHCP (Dynamic Host Configuration) | Stateless Address Autoconfiguration (SLAAC) or DHCPv6 |
| IPSec Security | Optional add-on | Mandatory native built-in support |
| Checksum Field | Header checksum recalculated at every router | Removed (done at transport/data link layer for speed) |
• A Record: Maps Hostname ➔ IPv4 address • AAAA Record: Maps Hostname ➔ IPv6 address • CNAME: Canonical Name alias (maps name ➔ name) • MX Record: Mail Exchange (routes incoming emails) • TXT Record: Domain verification & SPF/DKIM anti-spam security.