ALGORITHMS
What is the name for a step-by-step process used to solve a problem?
An algorithm
What is the smallest unit of data in a computer called?
A bit
What protocol is used to load websites in your browser?
HTTP (or HTTPS for the secure version)
What do you call software designed to damage or gain unauthorized access to a computer?
Malware
What is the term for unequal access to technology across different groups?
The digital divide
What are the three building blocks of all algorithms?
Sequence, selection, and iteration
How many bits are in one byte?
8 bits
What does DNS stand for and what does it do?
Domain Name System. It translates human-readable domain names like google.com into IP addresses that computers use to find each other.
What type of attack tricks users into giving up passwords through fake emails or websites?
Phishing
What does it mean for software to be "open source"?
The source code is publicly available for anyone to view, use, modify, and distribute. Examples include Linux and Firefox.
What is the difference between a linear search and a binary search?
Linear search checks each element one by one and works on any list.
Binary search cuts the list in half each time but requires the list to be sorted first.
What is the decimal value of the binary number 1010?
10. (8 + 0 + 2 + 0 = 10)
What is a packet and how does data travel across the internet using packets?
A packet is a small chunk of data. When you send information over the internet it gets broken into packets, each one travels independently across the network potentially taking different routes, and they get reassembled at the destination.
What is the difference between symmetric and public key encryption?
Symmetric encryption uses the same key to encrypt and decrypt, so both sides need to share that key secretly. Public key encryption uses two keys — a public one anyone can use to encrypt a message, and a private one only the recipient has to decrypt it.
What is crowdsourcing? Give an example.
Crowdsourcing means using contributions from a large group of people online to complete a task or gather data. Wikipedia is a classic example — millions of users write and edit articles collaboratively.
What is the difference between lossless and lossy compression, and which would you use for a medical image and why?
Lossless keeps all original data intact. Lossy permanently removes some data to save space. You would use lossless for a medical image because losing any detail could affect a diagnosis.
If you have 4 bits, how many unique values can you represent?
2⁴ = 16 unique values (0000 through 1111)
Explain what happens step by step when you type a URL into your browser and hit enter.
Your browser asks DNS to look up the IP address for that domain. DNS returns the IP. Your browser sends an HTTP request to that IP address. The server receives it and sends back the webpage data in packets. Your browser reassembles the packets and displays the page.
What is a DDoS attack and why is it hard to defend against?
A Distributed Denial of Service attack floods a server with so much traffic it can't respond to real users. It's hard to defend against because the traffic comes from thousands of different devices simultaneously, making it difficult to tell legitimate requests from attack traffic.
How can bias enter an algorithm and what are the real world consequences?
Bias enters when the training data reflects historical inequalities or underrepresents certain groups. For example a facial recognition system trained mostly on light-skinned faces performs worse on darker skin tones, which can lead to wrongful identifications with real consequences for real people.
Explain what it means for a problem to be "undecidable"
An undecidable problem is one where no algorithm can ever solve it for all possible inputs.
Why does digital data representation always involve some level of abstraction?
Computers can only store 0s and 1s, so all real-world data has to be converted into binary.
What is the difference between the internet and the World Wide Web? Why do people confuse them?
The internet is the physical infrastructure — cables, routers, and the protocols that connect devices globally. The World Wide Web is just one service that runs on top of it — the system of websites and links accessed through a browser. People confuse them because the web is the most visible thing they do on the internet, but the internet also includes email, video calls, online gaming, and more.
Explain how public key cryptography works using an analogy. Why is it more secure than sharing a single private key?
Imagine a padlock anyone can snap shut (the public key) but only you have the key to open (the private key). Someone puts their message in a box, snaps your padlock on it, and sends it. Only you can open it. It's more secure than a shared key because you never have to send your private key anywhere — it never travels over the network where it could be intercepted.
A company trains an AI hiring tool on 10 years of past hiring data. Explain two ways this could produce biased outcomes and what should be done about it.
First, if the company historically hired more men for technical roles, the algorithm learns to favor male applicants even if gender is not an explicit input. Second, if certain schools or zip codes were overrepresented in past hires, the algorithm disadvantages applicants from other backgrounds. To fix this, the company should audit the training data for representation, test outputs across demographic groups, and have humans review decisions the algorithm flags.