Computer Studies 2025 Jamb Examination

In a database, a query is a request for information. Its primary job is to retrieve specific data that meets certain conditions (criteria) from one or many tables. For example, you could use a query to find 'all students who scored above 70 in Biology'. Forms are for interfaces, and Reports are for visual representation.

Compression (often called zipping) serves two main purposes: it reduces the total file size to save space, and it combines multiple files into a single archive (.zip, .rar). This makes it much more convenient to send a folder full of documents as a single email attachment.

The main power of spreadsheets is automation. By using cell references (like \( =A1+B1 \)) instead of constants (like \( =10+20 \)), the result of the formula will automatically update whenever the values in cells A1 or B1 are changed. This reduces the need to manually rewrite formulas every time the data changes.

System software (which includes the Operating System) manages the computer's basic functions. It acts as an intermediary layer that allows application software (like a web browser or Word) to communicate with the physical hardware (like the CPU, RAM, and printer) without the app needing to know the technical details of the hardware.

Binary strings (like 101011110010) are extremely long and difficult for humans to manage without errors. Hexadecimal (Base-16) is used as a shorthand because one hex digit represents exactly four binary bits. This makes memory addresses and color codes much easier to read and write for programmers while remaining perfectly compatible with the computer's binary logic.

A Denial-of-Service (DoS) attack (or a Distributed Denial-of-Service, DDoS) works by flooding a target with more requests than it can handle. This overwhelms the server's resources (like CPU or bandwidth), causing it to crash or become so slow that legitimate users cannot access the service.

Phishing is a form of social engineering where attackers send fraudulent emails that appear to be from reputable sources (like banks or social media). The goal is to trick the victim into clicking a malicious link or revealing sensitive data like passwords and credit card numbers.

Microcomputers are the most common type of computers used today, including desktops, laptops, and tablets. Because they are affordable and powerful enough for everyday tasks like word processing and web browsing, they are the standard choice for small businesses and individuals.

An interpreter translates and executes code line by line. In contrast, a compiler translates the entire source code into machine code at once before execution. Therefore, option D is a characteristic of a compiler, not an interpreter.

The Hierarchical database model organizes data in a tree-like structure. In this model, each 'child' record has only one 'parent' record, similar to a file system folder structure. This is different from the Relational model, which uses tables, or the Network model, which allows multiple parents.