In computer systems, there are various techniques and mechanisms employed to manage and optimize the execution of processes and tasks. Two such techniques are swapping and context switching. Although they both play a role in improving system performance and multitasking capabilities, they serve different purposes and operate at different levels within the system. Let's delve into the difference between swapping and context switching. What is Swapping? Swapping is a technique used in operating systems to manage memory resources efficiently. It involves moving an entire process or a part of it from main memory (RAM) to secondary storage (such as a ... Read More

In computer programming, system calls and library calls are essential mechanisms used to interact with the underlying operating system and perform various operations. While they both involve invoking functions or routines, there are distinct differences between system calls and library calls. Understanding these differences is crucial for developers to efficiently utilize these mechanisms in their applications. This article explores the dissimilarities between system calls and library calls, shedding light on their respective characteristics and functionalities. What is System Call? A system call is a mechanism provided by the operating system that allows user-level programs to request services from the operating ... Read More

Context switching is a fundamental operation performed by an operating system to manage multiple threads or processes in a multitasking environment. It involves saving the current execution context of a thread or process and restoring the execution context of another thread or process. This allows the operating system to quickly switch between different threads or processes, giving the illusion of concurrent execution. There are two types of context switches: "thread context switch" and "process context switch". Let's explore the differences between them. What is Thread Context Switch? A thread context switch refers to the process of saving the current ... Read More

In programming, system−level calls are used to interact with the operating system and perform various tasks. Two commonly used system−level calls are system() and execl(). While both these calls allow executing external programs, they differ in their functionality and usage. What is system() Call? The system() call is a higher−level function that allows the execution of shell commands or scripts. When system() is invoked with a command as its argument, it starts a new shell process, which then interprets and executes the specified command. The system() call provides a simple way to interact with the command line and execute external ... Read More

In UNIX−based operating systems, such as Linux, there are two types of CPU time that are commonly measured: user CPU time and system CPU time. These metrics provide insights into how the CPU resources are being utilized by different components of a system or process. Understanding the difference between user CPU time and system CPU time is essential for performance analysis and troubleshooting. What is User−CPU−Time in UNIX? User CPU time represents the amount of CPU time spent executing in user mode, which is the mode where application code runs. It includes the time spent executing the user's program ... Read More

Virtualization and hypervisor are closely related concepts in the field of computer science, specifically in the domain of system virtualization. While they are interconnected, they represent different aspects of the virtualization technology. What is Virtualization? Virtualization is a technique that allows the creation and operation of multiple virtual environments or virtual machines (VMs) on a single physical computer or server. It enables the sharing of hardware resources, such as processing power, memory, and storage, among multiple operating systems or applications. Each virtual machine functions as an independent and isolated entity, running its own operating system and applications. There are 4 ... Read More

Introduction A time−based access list is a feature in network security tools that enables network administrators to control the traffic through a network based on the time of day, week or month. This type of access list allows administrators to increase security by only permitting specific users or devices to access the network during certain times, while blocking others. Definition of Time−Based Access-List A Time-Based Access−List (ACL) is a set of rules used to filter traffic passing through a router or switch based on date and time parameters. It is an extended version of an Access Control List ... Read More

Introduction A Time Access List (TAL) is a security mechanism that provides access control to resources based on time. Essentially, it lets an administrator or system owner specify a list of users who can access particular resources during specified periods. For example, a company might use a TAL to allow employees access to sensitive data only during working hours. The TAL works by restricting access to specific resources at particular times or dates, making sure that only authorized users are granted entry. This process can be incredibly useful for organizations with multiple users who require varying levels of ... Read More

Introduction Cryptography is the practice of securing information and communication through the transformation of messages into unintelligible formats for unauthorized access. In modern communication, cryptography plays a vital role in ensuring that sensitive data transmitted over networks remains secure. Advances in technology have made it easier to store, transmit and disseminate information making cybersecurity more important than ever before. Definition of Cryptography Cryptography is derived from the Greek word kryptos meaning hidden or secret, and graphia meaning writing. It is the process of securing communication by converting plain text into code or cipher text using encryption algorithms so ... Read More

Introduction Software testing is an essential aspect of software development that ensures the quality and reliability of a software product. Testing involves executing test cases, which are designed to verify the functionality and behavior of the software. However, in reality, it is not always possible to execute all the test cases due to time and resource constraints. This is where test case prioritization comes into play. Definition of Test Case Prioritization Test case prioritization is a technique used in software testing to determine the order in which test cases should be executed based on their relative importance. ... Read More