Search for information using a computer. Lecture: Searching for information using a computer

Internet is a global computer network that unites many local, regional and corporate networks and includes tens of millions of computers.

Working in the network, you need to quickly navigate the available amount of information.

There are basically three main types of information retrieval:

1. 
   Indication of the page address;

1. 
   Moving on hypertext links;

1. 
   Access to a search engine.

Search system provides the ability to search for information on the Internet.

Most search engines look for information on World Wide Web sites.

Yandex - Russian system search on the web. The company's website, Yandex.ru, was launched on September 23, 1997.

A distinctive feature of Yandex is the ability to fine-tune the search query. This is implemented through a flexible query language (slide 13).

Google. en

The leader of search engines on the Internet. According to one version, Google is a distorted spelling of the English word googol. "Googol (googol)" is a mathematical term denoting a unit with 100 zeros (slide 14).

Rambler. en

Rambler was founded in 1996.

The Rambler search engine understands and distinguishes between Russian, English and Ukrainian words. By default, the search is based on all forms of the word.

^ Transferring information between computers

According to the speed of information transfer, computer networks are divided into low-, medium- and high-speed.

According to the type of transmission medium, they are divided into coaxial, twisted-pair, fiber-optic networks, with the transmission of information via radio channels, in the infrared range.

^ Internet Addressing

In order to communicate with a certain computer on the Internet, you need to know it unique internet- the address. There are two equivalent address formats that differ only in their form: IP address and DNS address.

IP - address

An IP address consists of four blocks of numbers separated by dots. He can

look like this: 84.42.63.1

Each block can contain a number from 0 to 255. With this organization, over four billion possible addresses can be obtained. But since some addresses are reserved for special purposes, and blocks are configured depending on the type of network, the actual number of possible addresses is slightly less. The concept of "host" is closely related to the concept of an IP address. A host is any device that uses the TCP/IP protocol to communicate with other equipment. It can be not only a computer, but also a router, hub, etc. All these devices connected to the network must have their own unique IP address.

DNS - address

The IP address has a numerical form, as computers use it in their work. But it is quite difficult to remember, so the domain name system was developed: DNS.

The DNS address includes more user-friendly letter abbreviations, which are also separated by dots into separate information blocks (domains). For example: www.klyaksa.net

If you enter a DNS address, it is first sent to a so-called name server, which converts it into a machine-readable 32-bit IP address.

^ Domain names

A DNS address usually has three components (although there can be as many as you like).
Domain system names has hierarchical structure: top-level domains - second-level domains and so on. Top-level domains are of two types: geographical (two-letter - each country has its own code) and administrative (three-letter).

Russia owns the geographic domain ru.

The portal www.klyaksa.net registered the second-level domain klyaksa in the administrative top-level domain net.

The names of computers that are Internet servers include the full Domain name and the actual computer name. So the full address of the portal looks like www.klyaksa.net

gov - government agency or organization
mil - military establishment
com - commercial organization
net- network organization
org - an organization that does not belong to any of the above

Computer communications are necessary for the exchange of information between computers and the use of shared resources. To transfer information from one computer to another using computer networks can be used:

• 
  email;
• 
  world information network Internet;
• 
  search engines;
• 
  real-time communication;
• 
  file archives.

Email

The next type of information transfer is e-mail, or E - mail. It is designed to transfer files of any type over the network. One of its main advantages is cheapness and speed.

^ Email is historically the first information service computer networks and does not require mandatory availability high-speed and high-quality communication lines.

Any Internet user can get his "mailbox" on one of the Internet mail servers (usually on the provider's mail server), which will store sent and received emails.

At Email there are advantages over telephone connection. Telephone etiquette is very strict. There are many cases when you can not call a person for reasons of etiquette. E-mail requirements are much softer. By e-mail, you can contact an unfamiliar person or a very busy person. If he can, he will answer.

^ To email reached the addressee, it, in addition to the text of the message, must necessarily contain the email address of the recipient of the letter.

An email address is written in a specific form and consists of two parts:
username@servername

The user_name is arbitrary and is set by the user; server_name is hardwired to the user's choice of the server on which he hosted his mailbox.

Example, [email protected]

To send an e-mail, the sender must connect to the Internet and transfer to their mail server message. The mail server will immediately send this letter through the Internet mail server system to the recipient's mail server, and it will get into his mailbox.

However, the recipient will receive the email only after he connects to the Internet and "downloads" the mail from his mailbox to your own local computer.

^ UseNet newsgroups

UseNet newsgroups are electronic forums. Internet users send their messages there, in which they speak on a specific topic. Messages are sent to special discussion groups - teleconferences, while each opinion becomes available to all members of a particular group. Today, UseNet has over 20,000 newsgroups on a variety of topics: computers, recipes, genetic engineering, and more.

^ Transfer Protocol FTP files

The FTP file transfer protocol is used to transfer files with distribution copies of programs from remote servers to your computer. Depending on your rights ordinary user or others) You can perform certain actions in relation to the remote server (in most cases, this is a copy of the information available on it).

Telnet program was designed to provide remote access to remote computer in Internet. In this case, the user's computer acts as a terminal connected to big computer. Unlike computers, terminals do not have their own computing capabilities. They only provide access to some kind of computer thanks to their monitor and keyboard. An example is systems at airports, railway stations, where you can get information about tickets, flights, etc.

Finding information using a computer

Searching for information on the Internet

Software search servers

Purpose WEB

Use of key phrases

Keyword Search

Search term combinations

Search term combinations

Search term combinations

After some time working at the computer, you will find that you can not always remember the place where this or that document you need is located. In this case, you should use the information search tools included in the operating system. In this case, you should remember that for a successful file search, you must correctly specify the search criteria.

In general, it is convenient to search for information in Windows XP by selecting the main menu command Find (Search). This will launch windows explorer in search mode for files and folders. If you are already working with Explorer, you can start searching for the file you are looking for without leaving this program. To use the information search tools, you need to click the button on the explorer toolbar. In this case, the button will be fixed in the pressed state, and a panel with a group of controls for setting up the search will appear in the left part of the program window. With their help, you can set search criteria and give a command to start the search procedure for the desired file.

Most often, files are searched for by name and type, that is, by their extension. If the file name is known along with the extension, it is entered in the upper input field. We remind you that the name is separated from the extension by a dot. In the drop-down list Where to search (Folder) select the drive or folder in which you want to search. By default, you are offered the current folder, the contents of which are displayed in the right part of the program window. You can set the search across all drives on your computer, but specifying the search location will speed up the search significantly. You can complicate the search conditions by setting in the Search text input field (Containing text) a phrase that should be contained in the searched file. However, keep in mind that searching through the contents of files can take a very long time.

It often happens that the file name is not fully known. In this case, when searching, the missing part of the file name or extension is replaced with special wildcard characters? The * character replaces any number of any characters, for example, a wildcard search *.* searches for all files. Templates like *.htm or *.doc are often used, i.e. search templates for all files of a given type. Symbol? in the pattern replaces only one, but any character, for example, according to the pattern D? The files House and Smoke will be found. If the file name has spaces inside, for example, consists of several words, then when searching, this name must be enclosed in quotes, for example, “Favorite song.wav”.

Once you have entered your search criteria, you can start searching for files. The search starts after clicking the Search Now button. As you find the files and folders you need, their icons will appear on the right side of the Explorer window. The search may take a long time. You can stop the search procedure at any time by clicking the Stop Search button. Based on the search results, a list of files matching the specified search conditions is displayed. You can work with files from the list, but sometimes it is useful to navigate to the folder where the desired file. To do this, select one of the found files and click the button located on the toolbar. The desired folder will become current and you can continue working with it in the usual way. At the same time, the panel with the search settings fields will be removed from the Explorer window. You can also stay working in the system folder with search results. If the search settings panel bothers you, click the button on the toolbar, and this panel will be removed.

At the bottom of the search customization panel, there are several links to search for computers on the network, people, or information on the Internet. We will not dwell on the features of such a search, but note that the search principles always remain the same. You specify the search scope and criteria, and then start the search procedure. But back to finding files and folders on your computer.

It often happens that you do not know the name of the file you are looking for, but you know the date of its creation or its size. In this case, you can search for these file parameters. Such a search is needed if you need a list of files created, for example, in the last two days. These search options are set using additional customization fields that appear in the search panel when you click on the Search Options link (Fig. 2.13). The search type is set by setting the corresponding checkboxes. When you select specific checkboxes, additional fields appear below them to refine your search criteria. Check the Date box, and fields below will appear to customize the search by file date

If you check the Type (Type) and Size (Size) checkboxes, deselecting the Date checkbox, other fields will appear in the panel. As in the case of searching by date, you can select the type and size of the searched file. Moreover, you can specify the minimum or maximum size file. The last checkbox Advanced Options allows you to check or uncheck several checkboxes that specify how the search is performed. You can set the search view system folders and hidden files, but you can not search among them. You can also set the search in subfolders. If you remove this icon, the search will be performed among the files in only one folder. When searching, you can take into account the difference between lowercase and uppercase letters, or you can ignore such differences. By configuring various search parameters, you can significantly increase its effectiveness. Clicking on the heading of the Search Options frame will remove the additional fields from the Search Options panel.

After some time working at the computer, you will find that you can not always remember the place where this or that document you need is located. In this case, you should use the information search tools included in the operating system. In this case, you should remember that for a successful file search, you must correctly specify the search criteria.

In general, it is convenient to search for information in Windows XP by selecting the main menu command Find(Search). This will launch Windows Explorer in search mode for files and folders. If you are already working with Explorer, you can start searching for the file you are looking for without leaving this program. To use the information search tools, you need to click the button on the explorer toolbar. In this case, the button will be fixed in the pressed state, and a panel with a group of controls for setting up the search will appear in the left part of the program window (Fig. 2.12). With their help, you can set search criteria and give a command to start the search procedure for the desired file.

Rice. 2.12. Finding files and folders

Most often, files are searched for by name and type, that is, by their extension. If the file name is known along with the extension, it is entered in the upper input field. We remind you that the name is separated from the extension by a dot. drop down list Where to look(Folder) selects the drive or folder to be searched. By default, you are offered the current folder, the contents of which are displayed in the right part of the program window. You can set the search across all drives on your computer, but specifying the search location will speed up the search significantly. You can complicate the search conditions by setting in the input field Search text(Containing text) a phrase that should be contained in the searched file. However, keep in mind that searching through the contents of files can take a very long time.

It often happens that the file name is not fully known. In this case, when searching, the missing part of the file name or extension is replaced with special wildcard characters? The * character replaces any number of any characters, for example, a wildcard search *.* searches for all files. Templates like *.htm or *.doc are often used, i.e. search templates for all files of a given type. Symbol? in the pattern replaces only one, but any character, for example, according to the pattern D? m the files House and Smoke will be found. If the file name has spaces inside, for example, consists of several words, then when searching, this name must be enclosed in quotes, for example "Favorite song.wav".

Once you have entered your search criteria, you can start searching for files. The search starts after pressing the button Find(Search Now). As you find the files and folders you need, their icons will appear on the right side of the Explorer window. The search may take a long time. You can interrupt the search procedure at any time by pressing the button Stop(Stop Search). Based on the search results, a list of files matching the specified search conditions is displayed. You can work with files from the list, but sometimes it is useful to navigate to the folder where the desired file is located. To do this, select one of the found files and click the button located on the toolbar. The desired folder will become the current folder, and you can continue working with it in the usual way. At the same time, the panel with the search settings fields will be removed from the Explorer window. You can also stay working in the system folder with search results. If the search settings panel bothers you, click the button on the toolbar and this panel will be removed.

At the bottom of the search customization panel, there are several links to search for computers on the network, people, or information on the Internet. We will not dwell on the features of such a search, but note that the search principles always remain the same. You specify the search scope and criteria, and then start the search procedure. But back to finding files and folders on your computer.

It often happens that you do not know the name of the file you are looking for, but you know the date of its creation or its size. In this case, you can search for these file parameters. Such a search is needed if you need a list of files created, for example, in the last two days. These search capabilities are set using additional customization fields that appear in the search bar when you click on the link. Search options(Search Options) (Fig. 2.13). The search type is set by setting the corresponding checkboxes. When you select specific checkboxes, additional fields appear below them to refine your search criteria. Check box date(Date), and fields for setting up search by file date will appear below (Fig. 2.13,).

Rice. 2.13. Additional fields for setting search parameters

If you check the Type (Type) and The size(Size) by unchecking date(Date), other fields will appear in the panel (Fig. 2.13. As in the case of searching by date, you can select the type and size of the searched file. Moreover, you can specify the minimum or maximum file size. The last checkbox Extra options(Advanced Options) allows you to check or uncheck several checkboxes that specify the features of the search (Fig. 2.13). You can choose to view when searching for system folders and hidden files, or you can choose not to search among them. You can also set the search in subfolders. If you remove this icon, the search will be performed among the files in only one folder. When searching, you can take into account the difference between lowercase and uppercase letters, or you can ignore such differences. By configuring various search parameters, you can significantly increase its effectiveness. Mouse click on frame header Search options(Search Options) will remove additional fields from the search settings panel.