Virtual ports manage network traffic and serve as dedicated lanes for specific applications. TCP and UDP are two main types of virtual ports based on IP protocol. Ports range from 0 to 65535 and are used for various protocols like FTP, SSH, and DNS
Ethernet devices consist of MAC, PHY, and magnetics circuit for signal transmission. MAC controls addressing and data packet assembly. PHY converts digital data to analog signals for transmission. Magnetics provides isolation and termination according to 802.3 standard
Serial communication transmits data bit by bit over time. UART is a simple 8-bit protocol using single data line. RS-232 converts 5V UART to higher voltage for long-distance communication
HTTP is an application-layer protocol for transmitting hypermedia documents. Follows client-server model with connection establishment and response waiting. Stateless protocol, cookies add state to some client-server interactions
Frederick Stanley Mockford created "mayday" in early 1920s at Croydon Airport. Term combines French "m'aidez" (help me) with English pronunciation. Introduced for cross-Channel flights in February 1923. Adopted by International Radiotelegraph Convention in 1927
Well-known ports (0-1023) are used by system processes requiring superuser privileges. Registered ports (1024-49151) are assigned by IANA for specific services. Dynamic ports (49152-65535) are private and cannot be registered