5. internet and its uses

Internet

Internet

global aggregation of different computer networks

World wide web

collection of websites and web pages accessed using the internet

Uniform Resource Locater (URL)

• used to locate and access web pages

Hypertext Transfer Protocol (HTTP)

a protocol for computers to request and share the web pages

Hypertext Transfer Protocol Secure (HTTPS)

an encrypted form of information transfer on the internet

Hypertext Markup Language (HTML)

language used to compose web pages

Web browser

software which renders HTML and display web pages

Other functions of web browser

• storing bookmarks and favourites

• recording user history

• allowing use of multiple tabs

• storing cookies

• providing navigation tools

• providing an address bar

Retrieval and location of web pages

1. browser sends URL to the Domain Name Server (DNS)

2. DNS looks up the domain name in its index and matches it with the corresponding IP address

3. DNS sends the IP address back to the browser

4. browser sends a request to the IP address of the web server

5. web server responds by sending the HTML content of the requested web page to the browser

6. browser interprets the HTML content received and displays the web page to the user

Cookies

small files stored on the user's computer generally used to track user data

Session cookies

cookies stored in RAM and deleted when the browser is closed

Persistent cookies

cookies that are stored in hard drive even after a session ends

Functions of cookies

• saving personal details

• tracking user preferences

• holding items in an online shopping cart

• storing login details

Digital currency

payment method which exists only in electronic form and is not tangible

Blockchain

digital ledger, that is a time-stamped series of records that cannot be altered

Brute force attack

• hackers try to guess passwords by typing all possible combinations of letters, numbers and symbols

• to get access to user's personal data

Data interception

• stealing of data by tapping into a wired or wireless transmission line

• to cause computer to crash, delete data

• wardriving: act of locating and using wireless internet connections illegally

• packet sniffing: uses packet sniffers to examine packets sent over a line and sent back to attacker

Distributed denial of service (DDos)

• attack that uses multiple computers in a botnet to flood a part of a network with requests

• to prevent users from accessing a part of a network

Denial of Service (DoS)

• attack by a single attacker to flood a part of a network with requests

• to prevent users from accessing a part of a network

Hacking

• act of gaining illegal access to a computer system

• to gain personal information, corrupt data, test strength of security system

Malware

• virus: infects computer by attaching to programs, spreads when programs run

• worm: self-replicates, spreads through networks

• ransomware: encrypts files, demands payment to unlock

• adware: displays unwanted ads, redirects users to other websites

• spyware: secretly gathers user data, including browsing habits and passwords

• Trojan horse: disguised as legitimate software, tricks users into installing, steals data

Phishing

• attackers send out legitimate-looking emails

• to bait the user into giving out their information

Pharming

• attacker installs a malicious code on the computer which directs user to fake websites

• to bait user into giving out login and other personal details

Social engineering

hackers use their social skills to trick people into revealing access credentials or other valuable information

Access levels

settings that determine who can access an item and what they can do with it (read, write, delete)

Antivirus

software that is specifically designed to detect viruses and protect a computer and files from harm

Authentication

user proving who they are through username and password, biometrics, two-step verification

Automatic software updates

automatic updates fix vulnerabilities and patches to protect against major security threats

Checking spelling and tone

fake emails tend to have wrong spelling and grammar, tone may seem urgent

Firewalls

hardware or software which monitors the traffic between a network and user's computer

Proxy servers

acts as an intermediate between the user's computer and web server

Privacy settings

limits who can access and see a user's profile

Secure Socket Layer (SSL)

standard technology for securing an internet connection by encrypting data sent between a website and a browser