Computer Fundamentals and System Concepts

Virus scanners (often referred to as virus removers or antivirus software) search for known patterns or signatures of malicious code within files.

The kernel is the core component of an operating system that manages hardware resources and provides the lowest-level interface for software.

Monitoring programs are designed to run in the background and observe system activity for suspicious patterns. Integrity checkers typically verify file signatures rather than continuously monitoring I/O operations for behavior.

SISD stands for Single Instruction, Single Data. It represents the classic von Neumann architecture where one instruction is executed on one data element at a time.

A supervisor call (SVC) is a specific instruction that allows a user program to request services from the operating system kernel. It triggers a transition from user mode to supervisor mode.

MISD stands for Multiple Instruction, Single Data. This architecture involves multiple processors executing different instructions on the same data stream.

SIMD stands for Single Instruction, Multiple Data. This architecture allows a single instruction to be applied to multiple data elements simultaneously, common in vector processing.

MIMD stands for Multiple Instruction, Multiple Data. This is the most common architecture for parallel computing, where multiple processors execute different instructions on different data.

NORMA stands for No Remote Memory Access. It is a distributed memory architecture where each processor has its own local memory and cannot access the memory of other processors.

A distributed computer system is defined as a collection of independent computers that appear to the user as a single coherent system through communication and cooperation.

A distributed operating system manages the resources and communication across a collection of autonomous computers, providing a unified interface.

A Virtual Circuit (VC) is a means of transporting data over a packet-switched computer network in such a way that it appears as though there is a dedicated physical layer link between the source and destination end systems.

The CPU is composed of the Control Unit (CU), which manages instructions, the Arithmetic Logic Unit (ALU), which performs calculations, and the Memory Unit (often registers/cache).

The clock chip, often part of the Real-Time Clock (RTC) circuit, is integrated into the motherboard to keep track of the system time even when the computer is powered off.

Firmware is software that is permanently programmed into a hardware device's read-only memory (ROM), providing the necessary instructions for the device to function.