sockets and ports??

i was reading an article and came across the term 'socket' but wasnt sure what it was exactly. i looked it up and found this definition:

(1) In UNIX and some other operating systems, a software object that connects an application to a network protocol. In UNIX, for example, a program can send and receive TCP/IP messages by opening a socket and reading and writing data to and from the socket. This simplifies program development because the programmer need only worry about manipulating the socket and can rely on the operating system to actually transport messages across the network correctly. Note that a socket in this sense is completely soft - it's a software object, not a physical component.


a sockets a software ofject that can transmit data from applications. well isnt that what is port is as well?

PORT(2) In TCP/IP and UDP networks, an endpoint to a logical connection. The port number identifies what type of port it is.


thats what im confused about, and is the term socket relevant only to unix based systems as unix is mentioned twice in the definition. if anyone can clear that up for me that would be great. thanks in advance.

it applys to everything that uses the ISO's OSI reference model.

Ok, no it's not just for Unix. A socket (as far as I can remember with Windows) is the IP address plus the port number. So therefore, a node's IP address is specified to get to it, but the port determines what application will be communicated with. For example, if you wanted to communicate via a browser to the remote control software on a machine, if it was Win VNC, you could open up a browser and type in something like http://192.168.15.32:5810 , and there you have a socket. I hope this helps a bit.

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A socket (as far as I can remember with Windows) is the IP address plus the port number.

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i think this kind of clears it up a little more for me. so basically

SOCKET=(IP ADDRESS)+(PORT #)

is what you are saying. if so then i understand it much better. thank you.

p.s. its great that you can find a couple thousand people to 'clear things up for you' in times of doubt, and usually in a matter of minutes. thanks again :D

An even further way to understand it is this: Not only is a socket an IP addrews and a port #, it's a specific instance of an IP address + port #. Your OS's tcp/ip stack keeps these all organized and know which instance of which application, or which thread of which application is using which socket. Is this helpful, or have I just added more confusion??:)

Another way to think of it as... socket connects ur application to ur port .. so here lies the diffrence..and yeah its used on almost every OS

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and is the term socket relevant only to unix based systems as unix is mentioned twice in the definition

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sockets are available on Windows too, but in windows we have what is called the Winsock API which alows the programer to use sockets in Windows, http://www.sockets.com/

Edit:

A quote from http://w3.softlookup.com/activex/tax12.htm#E70E114

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Berkeley Software Distribution's UNIX was the first to incorporate socket style-routines. BSD UNIX was developed to be the universal interface to TCP/IP. Although it is still in wide use, it has fallen into a small niche as other network systems such as NetWare and Windows NT have taken a dominant position. The TCP/IP aspect of UNIX remains, though.

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Thats why the majority of the socket information available online talks mainly about *nix based operating systems.

good info and links aj.
thanx