Hi again everyone, it's been a while since I visited the forum. I've now got three books:
- HTML Dog - Patrick Griffiths
- Dom Scripting - Jeremy Keith
- Learning PHP & MySQL - Michele E. Davis & Jon A. Phillips
I've pretty much got to grips with HTML, CSS and Javascript, although I'm by no means an expert, but now my new book, 'Learning PHP and MySQL' has arrived and it's got me utterly stumped. I'll just give you a small extract from chapter 1:
Quote:
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Originally Posted by Learning PHP & MySqL
Some basic understanding of how the internet works may be useful if you haven't programmed for the web before.
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Fair enough, I suppose, so I continue reading, hoping to learn something:
Quote:
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Originally Posted by Learning PHP & MySqL
The HyperText Transfer Protocol (HTTP) defines how web pages are transferred across the Internet. ... The W3C and the IETF coordinated the development of HTTP, which is a request-and-response protocol that connects clients and servers. The originating client, usually a web browser is referred to as the user agent. The destination server, which stores or creates resources, and can contain HTML files or images, is called the origin server. Between the user agent and origin server there may be several intermediaries such as proxies.
An HTTP client initiates a request by establishing a Transmission Control Protocol (TCP) connection to a particular port on a remote host (port 80 is the default). An HTTP server listening in on that port waits for the client to send a request message. Upon receiving the request, the server sends back a status line, like "HTTP/1.1 200 OK," and its own response Depending on the status, this response could be the requested file, an error message, or some other information.
HTTP is built on top of TCP, which itself is layered on top of Internet Protocol (IP) The two are often referred to together as TCP/IP. Applications on networked hosts can use TCP to create connections to one another, and then exchange streams of data. The protocol guarantees reliable delivery of data from sender to receiver.
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As you can see I am absolutely bogged down by all this new information. I'll just say a couple of things I don't understand. What is a protocol, what does it do, how is it used, what uses it? What is TCP? WHat does it do exactly. What's port 80? Where is that? What does it do?
I could go on. Basically can anyone direct me to any resource that explains this in layman's terms? Thanks a lot!