Data transfer over the Internet starts with an event, for example, you start the browser (a client program) on your computer and request for some information, say an HTML file, located on a remote computer. There are two important ways in which information is requested from a browser, a hyperlink is clicked or a URL is entered in the browser.
The event can alsobe generated from the instructions of a program. We can automate uploaded and downloaded files (data transfer) with the help of a program.
When requested for an HTML document from a remote computer the browser searches for the remote computer and on locating it, passes the request to a program called the server running on this distant computer. The server then checks up your request and tries tolocate the HTML file on its hard disk. On finding it, the server sends this file to your computer. If this HTML document has embedded image, video, and/or sound files, the information and the content of such files are also passed to the browser.
On receiving data from the server, the client which is a browser in our case, starts to display the HTML page. The client holds the sole prerogative ondocument display, with no involvement from the servers' side. Once it sends the data to the remote computer, the server, don't worry about it. On receipt of all requested data, the client-server connection is lost. Thus, the next time this client asks for some information from the server, the server will treat it as a new request without any recollection of previous requests.
A protocoldetermines the direction of a message between two ports, and defines the valid types of messages that participants can exchange, defines the set of incoming and outgoing signals for a non-conjugate port. If the port is made conjugate, than the port will send the protocols incoming signals, and will receive the incoming signals. Protocols define the valid types of messages that can be exchanged betweenthe participants in the message.
Protocols represent a collaboration object that contains two roles that are connected to one another, protocols are binary, involving just two participants. In the binary protocols only one role needs to be specified when defining the protocol. The other side of the communication pattern can be derived from the base role by inverting the incoming and outgoingmessage sets.
I know the following protocols that do not appear in the text:
ICMP (Internet Control Message Protocol) control protocol messages on the Internet
SSH (Secure Shell) tries to make online communications more secure by encrypting all transmitted data.
“Understanding Web 2.0”
In web 1.0 its webmaster responsibility to keep the website updated and provides useful andinformative content to the end user. Examples of web 1.0 are double click, personal website etc.
Web 2.0 is more than search for information. Now user is searching for information as well as experience. Social Media Users wants to share their opinion, thoughts on his/her interested topic. Web 2.0 contains more organized and categorized content. Web 2.0 includes RIA (Rich internet applications) that is forshare their experience online.
Webmaster and user interaction no longer depends on direct means of communication rather a whole new system of social interaction has evolved that includes really simple syndication (rss feeds) and also the use of social networking sites.
I use many applications web 2.0 because allow me to interact with the environment through the internet, stay in touchwith my friends, faster access to information and online communication with people that use it too.
Regarding the top 3 social networks I cannot add already know, is a phenomenon used by millions of people because they allow people to voice their interests, preferences, activities, and above all, keep in touch with people...