A firewall is a crucial component of network security. Its primary function is to act as a barrier between a trusted internal network (like a home or corporate network) and untrusted external networks (like the internet). It achieves this by monitoring all incoming and outgoing network traffic and making decisions to allow or block specific data packets based on a set of predetermined security rules. This prevents unauthorized access, malicious attacks, and the spread of malware, thereby protecting the integrity and confidentiality of the internal network and its resources. Option (a) describes CPU optimization, (c) describes graphics software, and (d) describes a computer virus; none of these accurately define a firewall.

The ability of a computer to store and retrieve large amounts of data is directly attributed to its 'Data storage capacity'. Modern computers utilize various storage devices, such as Hard Disk Drives (HDDs), Solid-State Drives (SSDs), and network-attached storage (NAS) or cloud storage solutions, to permanently or semi-permanently hold digital information. While speed (Option A) refers to how quickly operations are performed, automation (Option B) refers to the computer's ability to perform tasks without human intervention, and reliability (Option D) refers to its consistent and dependable operation, none of these directly describe the function of retaining data. Storage capacity is the specific characteristic that fulfills this role, allowing for the archival and subsequent retrieval of extensive datasets.

Banks operate with immense quantities of sensitive data, including customer profiles, transaction histories, account balances, and loan details. To effectively manage, secure, and access this information, they rely heavily on Database Management Systems (DBMS). A DBMS provides the tools and infrastructure to define, create, query, update, and manage databases. This ensures data integrity, security, and efficient retrieval, which are critical for daily banking operations, regulatory compliance, and customer service. Word processing software is used for documents, presentation software for slideshows, and image editing software for graphics, none of which are designed for the complex, structured data management needs of a bank.

A byte consists of 8 bits and is the basic unit of information storage.

Digital banking services encompass both online banking (accessed via web browsers on computers) and mobile banking (accessed via dedicated apps on smartphones or tablets). Both allow customers to perform a wide range of financial transactions, such as checking balances, transferring funds, paying bills, and applying for loans, from their homes or offices without visiting a physical branch. In-person branch services require physical presence, and ATMs, while offering remote access, have a more limited set of functionalities compared to comprehensive digital banking platforms.

In computer science and digital technology, a 'byte' is the most widely recognized and fundamental unit for representing a block of eight bits. This grouping is significant because it is the smallest addressable unit of memory in most computer architectures and is sufficient to encode a single character (like a letter, number, or symbol) using character encoding schemes such as ASCII. A 'nibble' is half a byte (4 bits), a 'word' is a larger unit whose size varies depending on the computer architecture (often 16, 32, or 64 bits), and a 'kilobyte' represents 1024 bytes.

Booting (often shortened from 'bootstrapping') is the specific process that a computer undergoes when it is switched on or restarted. This process involves a series of self-tests (POST - Power-On Self-Test), followed by the loading of the essential components of the operating system from a permanent storage device (like a hard drive or SSD) into the computer's volatile memory (RAM). This allows the computer to become operational and ready for user interaction. While 'loading' and 'initializing' are parts of the overall boot process, 'booting' encompasses the entire sequence.

Read-Only Memory (ROM) is specifically designed to be non-volatile, meaning its data persists even when the computer is turned off. It stores essential firmware, such as the BIOS (Basic Input/Output System) or UEFI (Unified Extensible Firmware Interface), which are crucial for the computer's initial boot sequence. Unlike RAM, ROM contents are typically programmed during manufacturing and are not easily altered by the user. Random Access Memory (RAM) is volatile, losing its data when power is removed. CPU Cache is a small, very fast memory that stores frequently accessed data for the CPU but is also volatile. Virtual Memory is a memory management technique that uses disk space to simulate additional RAM but is not a physical memory type for startup instructions.

A computer system is fundamentally composed of two main categories: hardware and software. Hardware refers to all the physical, tangible components you can touch, such as the CPU, memory (RAM, ROM), storage devices (hard drives, SSDs), input devices (keyboard, mouse), and output devices (monitor, printer). Software, on the other hand, encompasses all the intangible instructions and programs that tell the hardware what to do. This includes operating systems, application programs, and utilities. Without both hardware and software working together, a computer system cannot function. Options B, C, and D represent specific subsets or functions within a computer system but do not collectively describe all its tangible and intangible components.

The network server is typically the central computer that manages resources and provides services to other computers in a network.