6. A SHORT INTRO ON HTTP and DNS

HTTP = Hyper Text Transfer Protocol

Used for responses in communication between the server and the client.

GET - fetch a resource from the server POST - submit data to the server PUT - updated a resource DELETE - remove a resource from the server

Response codes: 1xx: Informational 2xx: Succesful 3xx: Redirection 4xx: Client Errors 5xx: Server Errors

HTTP is stateless and in order to create persistence we use cookies.

DNS = Domain Name System

The names we give any resources connected to the internet like sites or IPs.

We can call it the Address Book of the internet as it stores this specific data.

Top level domains: .com / .org / .ro / .net etc Second level domains: tcmsec in tcmsec.com Subdomains: www, dev in dev.tcmsec.com

DNS Records

They provide information about domains

A record: maps a domain name to an ipv4 address MX record: specifies the mail server for a domain cname record: creates an alias for the domain