Lantech LGS-2624C User manual - page 266
H
HTTP
HTTP is an acronym for Hypertext Transfer Protocol. It is a protocol that
used to transfer or convey information on the World Wide Web (WWW).
HTTP defines how messages are formatted and transmitted, and what
actions Web servers and browsers should take in response to various
commands. For example, when you enter a URL in your browser, this
actually sends an HTTP command to the Web server directing it to fetch
and transmit the requested Web page. The other main standard that
controls how the World Wide Web works is HTML, which covers how Web
pages are formatted and displayed.
Any Web server machine contains, in addition to the Web page files it can
serve, an HTTP daemon, a program that is designed to wait for HTTP
requests and handle them when they arrive. The Web browser is an HTTP
client, sending requests to server machines. An HTTP client initiates a
request by establishing a Transmission Control Protocol (TCP) connection
to a particular port on a remote host (port 80 by default). An HTTP server
listening on that port waits for the client to send a request message.
HTTPS
HTTPS is an acronym for Hypertext Transfer Protocol over Secure Socket
Layer. It is used to indicate a secure HTTP connection.
HTTPS provide authentication and encrypted communication and is widely
used on the World Wide Web for security-sensitive communication such as
payment transactions and corporate logons.
HTTPS is really just the use of Netscape's Secure Socket Layer (SSL) as a
sublayer under its regular HTTP application layering. (HTTPS uses port 443
instead of HTTP port 80 in its interactions with the lower layer, TCP/IP.) SSL
uses a 40-bit key size for the RC4 stream encryption algorithm, which is
considered an adequate degree of encryption for commercial exchange.
I
ICMP
ICMP is an acronym for Internet Control Message Protocol. It is a protocol
that generated the error response, diagnostic or routing purposes. ICMP
messages generally contain information about routing difficulties or simple
exchanges such as time-stamp or echo transactions. For example, the
PING command uses ICMP to test an Internet connection.