HTTP Protocol Review

Flashcards covering HTTP concepts, requests/responses, headers, status codes, methods, security, and related topics.

HTTP

The protocol used for the World Wide Web; an application layer protocol used for messages between web clients (browsers) and web servers.

HTTP Request Message

A message sent from a web client to a web server, consisting of a header (with a request line and optional headers) and an optional body, separated by a blank line.

HTTP Response Message

A message sent from a web server to a web client, consisting of a header (with a status line and optional headers) and an optional body, separated by a blank line.

Request Line

The first line of an HTTP request header, containing the method (e.g., GET, POST), the URL, and the HTTP version.

HTTP Methods

GET (retrieve a resource), HEAD (retrieve only the header), POST (send data to be processed), PUT (upload a resource), DELETE (delete a resource), TRACE/OPTIONS (debugging), CONNECT (establish a two-way communication, e.g., for tunneling).

User Agent Header

An HTTP request header that provides information about the web browser being used to the server.

Host Header

A mandatory HTTP 1.1 request header that specifies the DNS name of the requested host, allowing multiple websites to be hosted on the same IP address.

Status Line

The mandatory first line of an HTTP response header, containing the HTTP version, a status code, and a descriptive phrase.

HTTP Status Codes

1xx (Informational), 2xx (Success), 3xx (Redirection), 4xx (Client Error), 5xx (Server Error).

Content-Type Header

An HTTP header that tells the client the MIME type of the resource being sent (e.g., image, movie, text).

Etag Header

A randomly generated string that is regenerated if a resource is updated.

Caching

A way to improve performance by storing resources locally to avoid re-downloading them.

Cookies

A way of maintaining state in HTTP via a data set that contains information to track and update user preferences.

X-Dash Headers

Custom HTTP headers prefixed with 'X-' that are not part of the official RFC and can be used for debugging

Basic Authentication

An authentication scheme in HTTP that transmits usernames and passwords encoded in Base64.

QUIC

A new version of HTTP combining TCP and UDP for increased throughput and faster startup time.