Theme 2. Software. Windows Ms-office. Information networks

Networks

Information processes - search, collection, storage, transmission, processing of information.

Computer network - a group of several computers, interconnected with the help of cables (radio channels) for the transmission of information.

Computer networks allow providing: collective processing of data by users connected to the network; sharing programs; sharing devices.

Networks are local, regional, global. Any network is built on the basis of several powerful computers - servers. To connect computers to the network, you need the appropriate network equipment and software.

Internet (Inter - a general Net - network) - a worldwide computer network, which unites tens of thousands of heterogeneous local and global computer networks into a single whole. The Internet is a grid of networks - the ability to transfer information between any computer around the world, regardless of their platforms.

The international network was created in the '60s within the framework of the military program and then turned into a global network of public use, which contains a huge amount of information resources.

Protocols are needed to organize the work of the PC in the grids. To date, the Transmission Control Protocol / Internet Protocol (TCP / IP) has been developed. World Wide Web (Simplified Web, WWW) works on the basis of this standard.

To work with the Internet you need an appropriate program, which is called a browser (browser - from the English to browse the book, scroll). 

With the Netscape Navigator and Microsoft Internet Explorer browsers, we have access to all of its resources to the Internet.

In addition to the communication line and the modem, you must have a provider - an organization that provides you access to the Internet. To get to the Internet you must first get to the node of the network (server).

Data transmission channels

Data transmission is realized through various channels: telephone cable; radio communication; electrical wires. 

The most reliable channel is a special communication channel (dedicated line).

Modem - converts a digital signal from the PC into an analog signal to transmit it along the line. The modem should be high-speed.

Connecting to the Internet through a cable TV network provides a higher data transfer rate of up to 10 Mbps.

A digital subscriber line (DSL) provides speeds up to 115 Kbc.

Domestic networks - a local network of the house (or several neighboring ones) via RadioEthernet indirect visibility or in another way creates a transmission channel. 

Advantages of a home network at a data rate (about 100 Mbps) that can be used for conferences, gaming battles, etc.

Internet services

Email - E-mail allows you to organize a single mail system within a diverse corporate network.

FTP and TFTP are tools for accessing file archives for file sharing between local and remote computers.

Teleconferencing - an e-mail message is sent to one address and automatically distributed to all conference participants (subscribers).

WWW is based on hypertext technology: it has a friendly interface; makes a transition on servers; searches for information on the hypertext web; allows you to easily work with graphics data in virtually all formats.

Web - document (Web - page) is an electronic document written in HTLM (* .htm) format and contains hypertext links.

The search server is a dedicated network of the Internet that searches, collects, and organizes information that is available on all other network servers, for example, HTTP: // yahoo.com.