Internet Tutorial

How does the internet work?

The Internet is a global association of computers that are permanently or temporarily connected to each other.

The computers that contain information such as this web site, are usually the clock connected to the Internet around.

Your computer that lets you retrieve this Web site is secure only temporarily connected.

You can then all active computers in the network to access and share information, eg send an email or web site read this.

The computers are connected via cable. Your modem encrypts and decrypts the information so that you will be able to transfer the telephone line over easy.

The reading of information is “Download”, sending “Upload called.

During a telephone set by entering a phone number to establish a permanent connection.

Raise the participants off, then you can usually make calls without being disturbed by this participant.

On the Internet, select next to your computer (usually at local rates) and transmitted to all this information.

This computer first analyzes the destination address. Is he with several computers connected permanently, so he passes the information to the entire computer, which can direct them at best.

If the destination address offline, that is just not connected to the Internet, then, depending on the type of information (eg email), these computers will be cached on one.

The target information is not on the Internet by specifying a telephone number, but by transmitting the destination address, the so-called URL (Uniform Resource Locator, eg https://sofitware.com).

In the language has “the URL” naturalized for the Web address of a document, query, etc..

Functional areas of the Internet
The Internet is divided into five functional areas:

E-mail
WWW (World Wide Web)
FTP,
Telnet,
Newsgroups

E-mail

E-mail is the function that is used most on the Internet. E-mail provides the fastest, most personal and intense exchange of information among users of the Internet.

Each user of the Internet will receive an e-mail address and then for all other participants, if this e-mail address to know his personally accessible. About this e-mail address can, for example personal information is requested, placed orders, or letters are sent.

WWW (World Wide Web)

The WWW form documents that can be linked via hypertext links to each other. Each document has a unique address (URL).

The address consists of the transfer protocol “http://” (Hyper Text Transfer Protocol) and the unique address on the claim of “www” for “World Wide Web”, so that for example the address is clear: “http: / / sofitware.com/go/ ”

The documents are stored on computers that are permanently connected to the Internet. Anyone who would like to publish documents on the Internet may do so, as a rule is an appropriate server space rented at an additional fee.

Some providers offer a free personal home page for personal use.

On the World Wide Web that is only the documents are available that are registered on a computer.

FTP (File Transfer Protocol)

The FTP protocol is used to transfer and handling of all files. You can use an FTP program to your rented space on an Internet server to manage for example.

Similarly, a file manager, you can thus your file from a disk directly transferred to the Internet server, then rename the file, delete or move into a new directory.

Telnet

Goes a step further than FTP Telnet. After logging in, you can own computer “remotely control the” start programs, then, and handle.

Newsgroups

News Groups (Usenet) are often called “bulletin boards called”.

Write to the general public a message and hope that someone will answer, or mix a strange conversation in one.

Newsgroups are organized according to theme, the quality of the talks is almost always dependent on the quality of the subject.

A newsgroup only works when holding the participants in certain manners. Newbies should first read along just before their own messages to the “bulletin board” to beat.

What is the role a browser?

A browser is a software program that transmitted data on your computer screen represents the.

The special thing about this is that users and creators of a Web site does not have to have the same operating system on.

Beginning of the Internet as the first computers were connected to the In, it was the biggest problem that the large computers were custom made. Each computer had a specific purpose to meet all its own programs and data.

So that the data could be shared, they agreed on a unified format. It was necessary, although still a separate program be written to and read data on the screen could display them. However, only one for each computer, and already the data could be exchanged.

This was the birth of the browser and HTML.

Although many computers are now standardized, this basic principle was retained, so that only a browser for every operating system is necessary today to read and evaluate the information to.

Web pages are therefore stored in so-called HTML (HyperText Markup Language).

The development of the browser, of course, went further. Today, not only HTML text, but graphics and programs in most browsers to display.

New features and capabilities of the latest generation browsers only be built in if all adhere to uniform standards.

Currently dominate the browser of Microsoft and Netscape to market.

Both seek separate agreement, additional features in their browsers work without. In order for these functions can be used by all, however, requires some compromises.

Is the payment by credit card over the Internet safe?

Payments are by credit card over the Internet unsafe.

However, this is due to a misunderstanding of the user, it is only by the providers themselves extremely high demands placed on security in order in advance of any abuse and thus prevent a loss of image.

“Security” means in the Internet, as a waiter never give the credit card (you do this again), receipts with your credit card number, etc. Keep any

Note in this context, the loan payment as at a gas station. Here credit must often not be given the hand of the user drags the map itself through the machine. This is the desired progress in the security of the already implemented now.

“Security” means in this context also indicate no bank on the letterhead!

Internet bookstores report for example, that – 70% of the customer to call 60 to be transmitted their credit card number. This is despite telephones and faxes can be intercepted, here is an “unsafe” payment method, the other replaced.

Everyone must therefore be estimated at the moment itself, an unauthorized withdrawal from his credit card he received would risk that. Security competes with the simplicity of the payment and the purchase of services and goods.

A little knowledge of human nature and control of credit card statements and bank statements can not harm intended.

It is common for credit card number over the Internet never send it via email to the, as emails can be read relatively easily.

Use when paying by credit card over the Internet is “safe forms”, including “secure forms” mentioned.

Such forms can also see the protocol specification. Here “http://” with “https: / /” replaced.

Another problem with credit card payments of course, is that the other person’s performance is not provided. “Prepaid on the Internet, never get”.

This problem is bigger than you may think, as the credit card of the product will be charged when sending. A package from abroad can be weeks on the road, stuck in customs, etc. So after 4-5 weeks then enters slight nervousness to have, the greater is the joy when it arrives 12 weeks later (as seen).

In Germany, the products sold are therefore mainly shipped cash on delivery.

It is relatively quiet lately about the “Virtual Pay” become, here you have to fax or phone your credit card number sent by and receive a PIN number. To pay, then enter your PIN number to only the seller then turns to Virtual Pay, they will send you an email if you agree the payment with. This you have then the words “Yes” to return (case-sensitive with), Virtual Pay paid to the seller and charge your credit card. All costs currently $ 5 for each year.

Similarly, the other payment announcements, such as e-cash or micropayments (payments of small amounts as the use of websites) so far no action followed.

The greatest hopes are currently at SET, MasterCard and Visa, the credit card payment, the safer is to significantly develop.

How does SET function?

How does credit card payment system, SET (Secure Electronic Transaction)?

SET is an open industry standard that payments on the Internet is more secure.

This should be the one hand, anonymous payment, on the other hand the dealer must also be given the security that the goods or service to be paid, especially since only be billed monthly often.

SET was developed by the two major credit card organizations, Visa and Master Card.

In June 1997, was released after one year of testing, the version 1.0.

The system is based on the system of anonymous payment.

The seller does not get more the customer’s name, credit card number, the credit card etc.

For this he gets encrypted, for him not to read credit card information he passes on to its merchant bank.

This company then made the actual payment. It can thus be anonymous payments.

In Germany, currently (Oct. 1997) € 5 million and 2.3 million Visa Card credit cards in circulation, Where we are approximately 334 million Visa cards and 160 million MasterCard (= Euro Card Master Card + + Access).

The actual procedure is technically very complicated.

You tell the dealer that you want to buy something
this will send two certificates, his own, which it legalized as a credit card payment recipients and a so-called public key of the so-called “Payment Gateways”.
This second certificate, you can encrypt your own credit card information so that the dealer, the information can no longer read. The whole is then put into a digital envelope, so that the information in transit can not be changed, and the dealer sent.
This transmits the data to its merchant bank, and expects an authorization.
The merchant bank may decrypt the information so far that they (credit card issuer) can identify the customer’s bank. To this it sends through the network of banks and the information expected from this one authorization.
The customer’s bank checks the credit worthiness of the customer and sends any authorization to the merchant bank.
The merchant bank then gives the dealer an own authorization.
The merchant ships the goods and sends the authorization of its merchant bank.
This concern about the authorization of the issuing bank the money and writes it to the dealer well.
The special thing about it, the complexity of encryption (cryptographic methods + digital signatures which can be verified that), whether the information conveyed in any way been altered.

So far, only a specification of standards-SET, SET-compliant software is expected in mid-1998.

FTP transfer stopped transferring, now what?

You’ll have to happen. While you are working in the Internet connection is interrupted.

No reason to fret. Only a complete restart, the home page called, and you must again go through all the ramifications of hypertext or form completely new to fill your.

In a form input, you should first fill out your form offline. (This way you can always challenge the way, if you must fill out the form long one).

Minimize your browser and then on the minimize icon in the upper right corner of the window.

Set the connection restores.

Then you enlarge the browser again by clicking the Start bar in Windows 95

The corresponding page or form are immediately available.

A document in HTML (Hypertext Markup Language is stored) is a simple text file (ASCII file) of the text additional commands, contains so-called tags.

You can view the document in the source code this if you eg Microsoft Explorer 3.0, the command “View / Source” or, in Netscape Navigator “View / Page Source” type 4.0.

At first glance, this language may look confusing, but it is quite simple and has “programming” nothing to do with.

Here, for understanding some of the commands:

A paragraph with normal text, the blank line is delimited by a contained within a tag.

This example, a new paragraph is

Many command be terminated by the same command, the prefix is a slash.

The title of a document, which is very important for search engines, is located within a

A horizontal ruler is generated by the command

, a line break by
.

The formatting of an HTML text are not comparable with those of a text program.

Originally, the Internet was indeed for the exchange of information among scientists. This content was more in demand as an optical design.

With the popularization of the Internet will probably change a place, however, large parts of the Internet continues to search text and information are used to.

There are, in the HTML language in addition to text only six shades for headlines