Digital Currency, Web Browsers, and Web Technologies

Flashcards covering key computer science topics including digital currency, blockchain, web browsers, cookies, DNS, and the difference between the Internet and WWW.

How does proof-of-work protect a blockchain network against unauthorized modifications?

Proof-of-work is the mathematical process required to add a block to a blockchain. It ensures it takes ten minutes to determine the necessary proof-of-work for each block before it can be added, policed by miners who receive a commission, making it impossible to attack all blocks simultaneously.

What are the main differences between session cookies and persistent cookies regarding storage location and lifespan?

Session cookies are stored in temporary memory and are deleted when the browser or website session is closed. Persistent cookies are stored on the user's hard drive and remain active until their expiry date (such as 6 months) or until manually deleted by the user.

What function does a Domain Name Server (DNS) perform when locating a web page?

A Domain Name Server (DNS) looks up the domain name contained in a URL within its table or cache to find and return the corresponding IP address that a computer needs to connect to the web server.

What is the primary difference between the Internet and the World Wide Web (WWW)?

The Internet is the worldwide collection of interconnected computer networks and physical infrastructure operating on TCP/IP protocols, whereas the World Wide Web (WWW) is a service on the Internet consisting of a collection of multimedia web pages and files accessed via a browser using HTTP/HTTPS protocols.

In the Uniform Resource Locator (URL) https://www.rockict.net/index.htm, what do www.rockict.net and index.htm represent?

www.rockict.net represents the domain name (or website address), and index.htm represents the file name (or webpage name).