2.1. HTTP About

• Request vs Response

• URI vs URL vs URN

• HTTP vs HTTPS

• HTTP/1.1 vs HTTP/2.0 vs HTTP/3

• Methods

• Statuses

• Headers

• Let's Encrypt - Free SSL/TLS certificates

• https://letsencrypt.org/getting-started/

• https://certbot.eff.org/instructions?ws=nginx&os=ubuntufocal

• HTTPbin.org https://httpbin.org/

• Petstore OpenAPI https://petstore3.swagger.io/