APCSP Internet Protocols

TCP/IP (Transmission Control Protocol/Internet Protocol)

a set of protocols used for transmitting data across networks, including the internet, where the first manages data transmission while the second routes packets.

HTTP (HyperText Transfer Protocol)

a protocol used for transmitting web pages over the internet, allowing web browsers and servers to communicate by transferring web pages and other resources; operates on a request-response model, where a client (browser) requests resources from a server; stateless, meaning each request is independent and does not retain session information

HTTPS (Hypertext Transfer Protocol Secure)

a secure version of HTTP that uses encryption via SSL/TLS to protect data during transmission, ensuring privacy and security while communicating over the internet.

DNS (Domain Name System)

a system that translates human-friendly domain names (like www.example.com) into IP addresses, allowing browsers to locate and access websites on the internet; operates through a hierarchical structure, with multiple levels of servers to resolve queries

IP addressing (IPv4 and IPv6)

the method of assigning unique numerical labels to each device connected to a network, ensuring communication within the internet

IPv4

a version of IP addressing that uses 32-bit addresses, allowing for approximately 4.3 billion unique addresses (which are nearly exhausted), commonly used in most networks today.

IPv6

a version of IP addressing that uses 128-bit addresses, significantly expanding the number of available unique addresses for devices on the internet, designed to address the shortage of IPv4 addresses.

FTP (File Transfer Protocol)

a standard network protocol used to transfer files between a client and a server on a computer network, enabling users to upload and download files; supports both anonymous and authenticated access, allowing users to upload and download files securely; operates on a client-server model and can use either active or passive modes for data transfer

client-server model

a distributed application structure that partitions tasks or workloads between service providers (servers) and service requesters (clients), allowing for efficient resource management and communication.

active mode

a mode in the FTP protocol where the client opens a port to listen for data connections from the server, which sends data to the client's designated port.

passive mode

a mode in the FTP protocol where the server opens a port and the client connects to it for data transfers, thus preventing issues with firewalls that may block incoming connections to the client.

SMTP (Simple Mail Transfer Protocol)

a protocol used for sending emails between servers in a reliable and efficient manner, defining the rules for email transmission; operates primarily over TCP port 25 and is responsible for the delivery of outgoing mail; not responsible for retrieving emails

ports

communication endpoints used by protocols to identify specific services or applications for data transmission.

POP3 (Post Office Protocol version 3)

a protocol used by email clients to retrieve emails from a mail server. It allows users to download email messages to their local devices and often deletes them from the server after retrieval to allow for offline access; simple and effective for users who access their email from a single device

IMAP (Internet Message Access Protocol)

a protocol that allows email clients to access and manage emails directly on the mail server; supports multiple devices, enabling users to view and organize their emails without downloading them; retains emails on the server, allowing for synchronization across devices

UDP (User Datagram Protocol)

a connectionless protocol used for transmitting data without establishing a connection; faster than TCP but does not guarantee delivery, order, or error correction; commonly used in applications where speed is crucial, such as streaming and gaming.

SSL (Secure Sockets Layer)

a protocol that provides a secure channel between two devices over the internet, encrypting data to ensure privacy and security during transmission; works to secure HTTPS; replaced by TLS

TLS (Transport Layer Security)

a protocol that ensures secure communication over a computer network by encrypting data and providing authentication to maintain privacy and integrity during transmission; used to secure HTTPS; replaced SSL