Internet Concepts and Characteristics

Internet Concepts

• The Internet is a network system of interconnected computers
• Computers use a common language for communication
• The Internet offers various services as a network of networks
• The Internet comprises interconnected heterogeneous networks
• Aims to form a unified global network
• The goal of the Internet is to share information

Characteristics of the Internet

• The Internet connects offices and labs to the local network
• Local networks connect to the Internet, similar to roads
• Highways allow vehicles to travel fast, whereas highways are similar to communication routes
• Local roads connect businesses
• The Internet is universal and available worldwide
• Allows users to access information, send emails, transfer files, and make purchases from any country
• The universality poses legal challenges because laws vary by country
• The internet is easy to use as technical knowledge is not needed
• The internet facilitates diverse content and can find almost anything
• The internet saves money by accessing information from home
• The internet reduces the need for libraries, conferences, or book purchases
• Facilitates collaborative work regardless of location through email, messaging or videoconferences
• The internet provides easy access to information, distance learning, banking, and service payments
• Free flow of information has fueled the Internet's rapid growth
• The protocol TCP/IP was made open for use
• Users can hide when reading or writing, though anonymity, aids free use but also facilitates crime
• No single entity controls or owns the Internet
• The Internet operates as self-regulated
• Most conventions are agreed upon by the Internet community
• The internet is chaotic because there are no strict rules
• Links may lead nowhere, some pages return errors, videos do not load or there are typos
• Internet information transmits via different means, mainly without encryption
• Communications can potentially be intercepted
• Sensitive data is encrypted before transmission
• Websites that handle financial data employ strong security
• These sites show a padlock icon in the navigator's status bar
• Security relies on encrypting valuable information so that it is illegible
• Threats include computer viruses that can harm data
• Viruses exploit browser or email vulnerabilities or are downloaded with files
• Updated browsers, avoiding suspicious sites, and using antivirus software can provide protection

Common Internet Language

• Protocol refers to established norms
• Norms include conduct, and design in technology
• In computing, a protocol the set of rules computers use to communicate over a network by exchanging messages
• It is a description of how computers communicate
• Communication is independent of whether they are mainframes, personal computers, notebooks, and smartphones
• Includes software or hardware such as:
  • HTTP for web pages
  • UTP cables
  • TCP for computer communication
  • IP for network communication
  • SMTP, POP3, and FTP for applications
• Transmission protocol TCP/IP is a system of communication between computers
• All data is split into small pieces or packets for transmission between computers

Client-Server Architecture

• Server side and the client side are distinct in the architecture
• Powerful machine provides a variety of services to networked clients
• Services include file management, printing, web pages, email, database updating, and access control
• The server accepts and processes requests, providing the result to the requester
• With TCP/IP, can be implemented as software applications on compatible systems
• Server time interacting with the client has no defined time length
• Servers can handle simple tasks and complex operations
• Simple servers handle requests one at a time
• Client occupies a computer demanding service from servers
• Can also perform processing locally via displaying web pages
• Client/server model is recommended for networks requiring high reliability
• Features
  • Centralized resources; the server controls resources
    • Example: base data
  • Enhanced security
    • Controlled access points
  • Server-level administration
    • Decreased involvement
  • Scalable Network
    • Easily add/remove clients without affecting function

Disadvantages of the Client-Server Architecture

• High cost; technical complexity of the server
• Single point of failure; due to the reliance that that client is built around

How a Client-Server System Works

• Clients send demands to servers using IP and port
• Server receives and responds to demand using the client equipment and port

Types of Internet Connections

• Internet service providers (ISPs) connect consumers to the Internet via different technologies
  • Technologies that connect to the internet include: DSL, cable modem, GSM, dial-up etc.

Dial-up

• Client uses a standard 56kbit/s modem to connect to the basic phone network
• The connection is slow compared to modern options
• Occupying the telephone line prevents phone calls
• Cost can approach broadband expenses as it connects to a data session

Broadband Connection

• The term generally refers to high-speed Internet access

• Defined as fast and always-on connection to Internet

• ADSL (Asymmetric Digital Subscriber Line)

  • Converts telephone wire to high-capacity data while maintaining voice service
  • Cost depends on connection speed instead of usage time
  • Takes advantage of the asymmetric technology that receives data more than it is sent
  • The ADSL2+ reaches up to 20Mbits speed

• Cable Modem

  • Modulates data signal over cable television infrastructure
  • Uses a TV signal channel for Internet access
  • A splitter is used to separate cable and web data signals
  • One neighborhood can share bandwidth over a cable
  • The connection speed varies
  • Connection does not rely on central office distance and can easily reach the average speeds based on the plan

• Satellite

  • Covers every area of the world that are limited to wired options
  • Satellite requires specific equipment with high cost
  • Offer lower bandwidths
  • High latency in data with slow processing speed
  • Suited well for line games and internet
  • High provider costs and signal loss from meteorological phenomenon like electrical storms

• Fiber Optic (FTTH)

  • Has greater range with higher bandwidth
  • Able to send greater amount of data with speedy rates
  • Lack of coverage that requires many economic investments

• Mobile Phones: 3G & 4G Data Connection

  • 3G is a mobile phone generation with data transfer capability
  • Data transfer enables downloading apps, sending/receiving emails, and instant messaging
  • Internet access is available in most locations, but data transfer speeds vary based on coverage
  • Another disadvantage is the elevated price of the equipment and quick access

Ways to Connect to the Internet

• Methods depend on contracts made with service
• Cable internet are dial up, ADSL or cable
  • Connected to the computer with a UTP5 cable that connects PC to modem

Wi-Fi Networking

• Wireless network connects nodes without physical cables
• Uses electromagnetic and radio waves
• Provides less speed and environmental interference
• Security may be difficult to establish as data packets may be easily intercepted

Roaming

• Wireless networks supports roaming
• A station that is mobile, such as a notebook, is able to move between access points, and buildings and users can move around
• WIFI makes internet access convenient and mobile but speed is reduced when increasing distance, or objects that block signal, such as walls
• A WiFi router has three types of interruptions:
  • Items that retain signals such as walls, soil and furniture
  • That mostly modify metal objects, and those that compete for the signal of a router are all wireless devices

Required Elements to Connect

• Terminal
  • Includes a desktop computer, notebook, netbook, cell phone, table, Smart-Tv, photocopier, printer, etc.
  • Requires sufficient memory to connect to the internet, and quality, speed and overall connection speed

Cable UTP

• Unshielded cable used for telecommunications
• Used to connect more than one PC to a home or building
• Not effective as the shield lacks remoteness
• Can have limited bandwidth speed

Modem

• Computer information is different from telephone communication
• Converting the 2 different ways of sending data is necessary for conversion
• Computer uses digital codes, and the telephone use physical

Placa de red

• The modem transfers from analog to digital
• Computer passes through modem to “modulate, or convert the data from telephone line, data is treated through a computer

Red

• Place it on motherboard or USB that can be used when accessing or sharing
• Cables use devices that uses red wi-fi

Swith

• Interconnects a number of computers and quickly examines data

Access Point (AP)

• A private wireless access point to connect (notebooks, cell phones, printers, computers, etc.) to the Internet without having cables allowing the user to place a red connection and sharing

Router

• Switch is different from a router and aims at routing the data for the packet
• Present the typical modem with inter router/ model that allows a sharing of data
• The router can be displayed on a red and circular scheme

Navigator

• A system that is capable of reading data that is stored on server is written in HTML languages, and is a structured and formatted way
• The input of the use is collected on a variety of forums
• These programs are called browsers that provide access to internet and are the most known, as internets, google, chrome, mozilla
• Has terminal and infrastructure with someone giving us access, and is provided, that the supplier gives access to internet (ISP)

Electronic Directories

• Used to find computer, and network resource
• 3 types
  • Computers (domains)
  • People (electronica media)
  • Resources (URL of the image)
• Consists of both optional and static directories

Computer directories

• Computer directory, as said, exists within a complex and structured directory

Machine

• Not necessarily a Pc such as, printer, device, and camera
• Unique IP, number
• Structured by 4 groups, numbers from 0-255, separated by periods

Domains

• People remember these names and numbers
• Names are used to find a domain

DNS every request

• Finds data, and finds IP
• Domain are separate by points, are computer and contain the page entity
• Internet and machines of organization and country

Electronic Directories

• Some features are visible

URL (Universal Resource Locator)

• A string of character code that points each unique code to data
• Audio, photos and documents

Services of Internet

• Worldwide web provides access to the information
• Is a means of accessing online information

Electronic Mail

• Is a system that transfers media to users and files
• Protocol SMTP that sends and POP which receive
• Requires mail, specific, emails
• Navigated access by email that connects
• Mail can send out
  • Writes out information that signs on to mail
  • Connects to port

Mail considerations

• Requires a key and password
• All emails require symbol
• All mail have address of electronic mail
• Mail store folders that receives and sends
• Easy name is best option
• Email names are used as gmail.com and name
• Spam is prohibited

Browsers and Search engines

• Browsers are applications that translate codes into language that can be read by user by using program
• Navigators communicate with the computer, through the protocol, HTTP

Navigator type

• Explorer and mozilla with google and opera

Search motors

• Is a software that seeks automatic websites
• Based on word, and allows users to find data

Searching

• 1994 north america created web
• Yahoo classified list spider
• Allows sites for tracking
• User asks search
• Shows relevance to searching

Things you can and cannot do on the internet

• Find large amounts
• Simple communication
• Accessibility
• High interactivity with user
• Able to make information, and cheap
• Altered
• Is an enormous count
• Information data
• False
• Easy to find data
• Misleading data

Searching

• Searching is complex
• Complex is a way of discovering

Searching of data

• Know why to process data
• Because specific data runs over, that chosen
• Control over internet data
• If data is not related

Data

• How to access it is effective or that sought
• Minimize access
• Demand initial
• Knowledge of facts
• Type of info and where info
• Planning requires that is needed
• Where to look for data
• With the knowledge what facts
• Where find data
• To narrow location
• Requires the internet with knowledge

Errors

• Order titles

Useful

• Quality data and information

Search

• Requires more facts for searching data
• Not all words are contained
• Uses other words

Importation

• Should search mayusculas, and titles with except with specific symbols

Simple

• Uses concept and adding code

More direct info

• That looks on simple, and most data should contain the facts

Direct for data

• Data should use data that is effective

Short facts

• What delimit the searches
• Sign and complement that help the user
• Comets
• Specific phrase

Locate for webs

• You can make data with specific terms

To reject

• Signs used to delete the facts

Spaces

• Asterisk with space

Only titles

• Title for the best result

Specific facts

• Filetype with extension