URL

What is a URL?

A URL (Uniform Resource Locator) is a complete web address that specifies the exact location of a resource on the internet. URLs provide a standardized way to identify and access web pages, files, images, APIs, and other resources. Every link you click or address you type in a browser is a URL.

URL Structure

https://www.example.com:443/path/page.html?query=value#section
  │       │      │       │         │            │         │
  │       │      │       │         │            │         └── Fragment
  │       │      │       │         │            └── Query string
  │       │      │       │         └── Path
  │       │      │       └── Port (optional)
  │       │      └── Domain name
  │       └── Subdomain
  └── Protocol/Scheme

URL Components

URL vs Domain vs URI

URL Encoding

Special characters require encoding:

Space → %20
& → %26
= → %3D
/ → %2F
? → %3F

Example:
"hello world" → "hello%20world"

URL Best Practices

For SEO

1. Use descriptive paths: /products/blue-shoes

2. Keep URLs short and readable

3. Use hyphens, not underscores

4. Lowercase letters preferred

5. Avoid parameters when possible

For Security

1. Always use HTTPS

2. Validate URL inputs

3. Avoid exposing sensitive data in URLs

4. Use canonical URLs

Common URL Protocols

URLs are the addressing system of the web, providing a universal way to locate and access resources across the internet.