Introduction

An interconnection of computer networks that allows computers connected to communicate directly with each other, for some Internet users, generates a feeling of closeness, empathy, understanding and discussion instead of confusion, struggle and conflict that they themselves refer to as life itself.
This emerged at several universities 1965, by the need to communicate with over the years this has suffered several changes and progress was very surprising. This allows us to transmit information from one place to another much faster.

The evolution

Taking into account the June 2006 to June 2008 there were almost one million new residential customers and more than 100,000 new organizations connected to the network.

Internet access

An ISP is a company (servers) that is dedicated to connecting to the Internet to multiple users or to different networks, as well as be responsible for maintaining the access for this to function properly. It is also responsible for hosting Web pages or domain registrars including

Different types of services for internet access

Basic Telephony Network

This was the first technology used for the Internet connection is based on communication through the telephone network already installed in homes by means of a modem (modulator - from modulator). Allowing all persons having telephone service can access the Internet. This was a big disadvantage for those who handle large amounts of data simultaneously also impossible to use your phone while online. This system is charged for time used.

With a modem that complies with the V.90 standard can reach speeds of 56 KBPS (7 KB / s)
There are now many companies offering their customers Internet access through this network.

ISDN

(Integrated Services Digital Network)
ISDN was a logical and necessary evolution of Internet access through the basic telephone network. This is an evolution of the perfection of the previous analogue lines, supporting the transfer of both voice (telephone) and data (Internet access).
For this, the ISDN line with two B channels KBPS 64 each, with a separate D channel of 16 KBPS, which is used to establish the call and signaling / synchronization between different network devices.

As with the basic telephone network, many companies offer connection via ISDN.

ADSL

It is a technology which provides broadband access to the client using the infrastructure of telephone lines. To do this, use the frequencies that supports copper cable, and are not used for telephone conversations, for transmitting and receiving data. To separate the frequencies that the telephone data, you must install a splitter, whose sole function is to separate and collect both signals.

As a main advantage is the same as the basic telephone network: the telephone lines are drawn by the majority of the national territory. However, for the connection to the Internet run smoothly, you must have a

Central ADSL at a distance not too great, that if the signal is not adequate.

Cable
Internet access via cable modem used as physical medium for data transmission and fiber optic cable can transmit (and receive) data at speeds much higher than those supported by copper cables conventional telephone lines.
In this case it will need a splitter to separate the different signals coming through the coaxial cable.
The main drawback of this technology is its high cost, in terms of infrastructure, for businesses that want to provide this service. As a result, the company offers services only in certain localities.

Pro obstetrician communication

Function is to transmit data from one user to another or from one group of them to another.

The Internet Protocol is a connection-oriented protocol used by both the origin and the destination for data communication over a packet switched network.

The data are sent in blocks known as packets (unreliable). In particular, IP does not require any configuration before a computer tries to send packets to another which had not been reported before. IP has no mechanism for determining whether or not a packet reaches its destination and only provides security (using checksums or checksums) of her head and not the data transmitted.

If the sending (programs data) exceeds the maximum size "negotiated" in the network segment on the circular will be divided into smaller packets and then reassembled when needed. These fragments may be each for a different path depending on the number of users connected to that network at that time.

The headers contain the IP addresses of the source and target machines (IP) address which consists of four numbers ranging from 0 to 255 and will be used by packet switches (switches) and routers (break) to determine the network segment on the forwarded packets.

The IP is the common element in the Internet today. The current and most popular network protocol is IPv4. IPv6 is the proposed successor to IPv4, the Internet is slowly draining the addresses it uses IPv6 source and destination addresses of 128 bits.
IP addressing and routing

IP Address

Addressing refers to the way it assigns IP addresses are divided and grouped and sub-teams, ie, a number that identifies a logical hierarchy and a device (a computer) in a network use the Internet protocol (Internet Protocol), which corresponds to the network-level or level 3 of the OSI reference model. This number shall not be confused with the MAC address is a physical number that is assigned to the card or network device (dictated by the manufacturer), while the IP address can be changed. All users are using an IP address, but this is changing every time the user connects (dynamic IP). Web Sites that by their nature need to be permanently connected, generally have a fixed IP address

Routing

Routing is to find a way to connect one network to another and although it is carried out by all the teams, is performed mainly by routers, which are nothing more than specialized computers receive and send packets through different network interfaces and provide security features, redundant paths and efficient use of resources.

Pro obstetricians of the application layer

Consider the modules of software protocols in a vertical stack consisting of layers. Each layer is responsible for managing a part of the problem.

application layer is closest to the user. At this level (7) defines the protocols that applications use to manage data and tools for sending this information through all the layers that continue to apply.

A large number of application protocols, many of them linked to a particular application. Protocols that are not commonly used users, but the programs they manage.
Services accessible by Internet

The different services you can have Internet access are provided by the protocols that belong to the application level. These protocols are part of the TCP / IP and must inter alia provide a standardized way to interpret the information, since not all machines use the same sets of characters or the same standards. The protocols of the other levels are only responsible for the transmission of information as a block of bits, without defining the rules to indicate how they should interpret these bits. The application-level protocols are intended for specific tasks, some of which are regarded as traditional Internet use since the inception of the network, for example:

File transfer (File Transfer).

Electronic mail (e-mail).

Remote connection (remote login).

Today the Internet allows us access to infinite amounts of services, from finding information to transact all remote sites.
With the so-called search engines, we can find a wide variety of information on any topic. This is a system that indexes files stored on Web servers through its "spider" (or web crawler).

Searches were done with key words or topics by hierarchical trees, the search result is a list of Web addresses that are mentioned in the issues related to the keywords searched. Can be classified into two types:

Index: These systems search for items or categories ranked. These databases of Web addresses produced "manually", ie people who are responsible for each web page to assign a category or topic.

Search Engines: These are systems of keyword search. Databases that are automatically web pages using "robots" search on the net.

Some of these services are:

Email:
Network that allows users to send and receive messages quickly. For a person can send a mail to another, both have an email address. This address has to give a mail provider, who offer the service of sending and receiving.

Chat Channels:
It is based on a set of servers that supports connections from any person anywhere on the Internet that can send and receive messages between users. The talks are organized into channels, which are run by operators who act as moderators.

Video conference:
We can say that the video is similar to instant messaging in a way, because through it we can exchange messages, files, etc.., Its potential is that it makes use of technologies such as WebCam, microphones and so on., Unlike some messaging programs that do not implement this type of hardware. Among the programs to find video Neetmeeting as the most popular.
Domain Name System

The Domain Name System (DNS) or Domain Name System enables users of a TCP / IP and hierarchical descriptive names to easily locate computers (hosts) and other resources in the network, thus avoiding having to remember IP address of each computer you wish to access. In essence, DNS is a distributed database containing associations of symbolic names to IP addresses. The fact that it is distributed can delegate control over various segments of the database to different organizations, but always so that the data of each segment are available throughout the network, through a client-server.

Programs called name servers (name servers) is the server side of client-server. Name servers contain information about some segments of the database and made available to customers, called solucionadotes

When someone enters an address in your browser, that address this by asking the name server of your ISP, and ask in the first instance who has information on the top level domain, TLD (. Com,. Net,. is so.) Once this information, the question of the TLD name server for the domain name in question. Finally he asked the organization by the name of second level domain name itself, which returns the name of the authoritative server, who knows the IP address you're looking for.
Browser or browsers

Clients are programs that allow users to access the service pages. Some of these programs are:

Internet Explorer

Netscape

Opera

Google chrome

Mozilla Firefox

Website
A website, also known as web page, a document is adapted for the Web and usually part of a website. Its main feature are the links to other sites, this being the foundation of the Web.
A page is composed mainly of information (text only or multimedia) and hyperlinks, or it may contain data associated style to specify how to display or to make it interactive embedded applications.
Page content can be predetermined or generated upon request or display a web server ( "dynamic web page"). Dynamic pages that are generated when the display is done through interpreted languages, usually JavaScript, and the application responsible for displaying the content is to be generated. The dynamic pages that are generated when requested by an application are created in the Web server that hosts them.

Regarding the structure of the websites some agencies, notably the W3C, often set policies with the intention of standardizing the design to facilitate and simplify the display and interpretation of the content.

Conclusion
When discussing the evolution of network we refer to the tool's largest technological world, a system of interconnected for the purpose of sharing information through computers, and various and easy access to humanity.
The Internet has a profound impact at the level of society in a changing world, not only at work but in leisure, especially in the knowledge, thanks to the millions who have immediate and unlimited access to a large and diverse information.

This has reached all parts of the world by opening a digital divide, today there is no place in the world that does not have at least one or two computers connected to the Internet.

This has been a great advantage because it allows people to access endless information. Furthermore, put an end to the isolation of cultures due to their rapid incorporation and mass, the virtual space is updated constantly to provide us information fresh, and somewhat irrelevant.

Like any great revolution, I believe a new era of different methods of solving problems created from previous solutions, increased its influence over many aspects of everyday life, with the appearance of and the high-speed connections available the public Internet to significantly alter the way people work by giving the power to do this from home, this tool allows people more flexibility in terms of time and location most conducive to their way of working.

The Internet has become the most used and highest growth in history, there are now many companies which are making money from advertising on the network, this system also offers many advantages both for users and for advertisers because in she navigates many people, but rather the growth or the incorporation of them that the streets of what at first was a small town called Internet becomes a highly interconnected world and among its members.

Obviously, this technological breakthrough as mentioned above entails a huge responsibility because through your slip arguments and themes that represent much of the traffic information

Compared to encyclopedias and traditional libraries, the Web has enabled a sudden and extreme decentralization of information and data. Some companies and individuals have adopted the use of weblogs, which are largely used as a daily updatable. Some commercial organizations encourage staff to integrate their areas of specialization in their sites, hoping to impress the visitors with expert knowledge and free information.

Internet-driven globalization and together with the so-called dematerialization has given birth to a new era characterized by the use of the network in each of the processes and aspects of human life, that through the it was devised to grow things and aspects of the Internet and do more essential to the world.

A major limitation for this service is the lack of security as it seeks to communicate a secret in an environment with millions of potential witnesses difficult and not likely to hear a conversation between two partners increases as does the distance. Since the Internet is truly global, not a secret value should be communicated through it without the help of cryptography. Everyone has the right to privacy when accessing Internet privacy need not go away.

Depending on the situation and needs of the client should be opting for one solution or another. Clearly, if the customer uses the Internet for entertainment with access through a telephone line that will have their needs met. Besides, this is the cheapest way.

Seen from an economic point of view we can say that these people could also choose to pay for connection time.

For people with slightly higher requirements or for applications that require their specific use ISDN line is the solution for which eligible.

If the client needs a high bandwidth, there are two alternative technologies: ADSL or Cable. The cable is more economical, but its installation depends on whether the area is one company offering this service.

In the search for certain information online, we use the information pages, these pages contain a fixed IP address (a 4-digit code from 0 to 255), allowing the site by the users.

This also happens the same in the transfer of information across users. This information is converted into packets and each user is assigned a dynamic IP.

"INTERNET IS A TREASURE TO MANAGE"