HTTP vs HTTPS, ports and common protocols
40 min · Intermediate
HTTP (HyperText Transfer Protocol) is the request-response protocol of the web, and HTTPS is HTTP sent inside an encrypted TLS connection. Placement rounds ask about both, plus a quick-fire list of well-known ports and protocols. Section 14 (Web Fundamentals, HTTP & REST APIs) covers HTTP in depth; this lesson is the interview revision.
Topics in this lesson
- HTTP methods and status codes at a glance
- HTTPS and TLS: certificates and encryption
- Common ports: 20/21, 22, 25, 53, 80, 443, 3306
- FTP, SMTP, SSH and other application protocols
- HTTP/1.1 vs HTTP/2 at a glance
Interview questions this lesson answers
- What is HTTP?
- What does it mean that HTTP is stateless?
- What is the difference between GET and POST?
- What is the difference between PUT and PATCH?
- What does idempotent mean?
- What are the classes of HTTP status codes?
- What is the difference between 401 and 403?
- What is the difference between 301 and 302?
- What is a 304 Not Modified?
- What do 502, 503 and 504 mean?
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