Data Flow Diagram (DFD) Symbols, Structures, and Design
Data Flow Diagram (DFD) Symbols
Entity: Represents users interacting with the system.
Data Flow: Represents communication between DFD symbols.
Process: Represents the phases that a system undergoes, interacting with incoming and outgoing data.
Data Store: Represents where information is stored in the system, either permanently or temporarily.
Data Structures
Logical Data Structure: Describes all information related to the system’s operation, implementation, and business requirements.
Physical Data Structure:
Read MoreUnderstanding Domains, Active Directory, and RAID Configurations
Domain
A domain is a set of user accounts and network resources under a single name, establishing security boundaries. Active Directory, installed on a Windows Server, manages the domain. Servers within a domain can be:
- Domain Controllers: These servers belong to the domain and hold a copy of user accounts and other Active Directory data. At least one domain controller is required.
- Member Servers: These servers store files and other network resources.
Workgroup
A workgroup is a basic grouping that
Read MoreFormatting Text and Paragraphs in Word Processors
Improving Text Appearance
It’s possible to change the font and size, highlight text with bold, italics, underline, or change paragraph alignment (left, center, right) and add borders. This process is called formatting.
There are two ways to format text:
- Write the document, select the text to modify, and apply the formatting.
- Choose the format first, then write the text.
Font and Style
Font refers to the characteristics of displayed and printed characters. The available fonts depend on the word processor
Read MoreUnderstanding the Windows Registry and Computer Viruses
1. What is the Windows Registry?
The Windows Registry is a database that stores configuration settings for Windows and other programs. It contains information about hardware devices, user preferences, and software settings. From Windows, which stores information about your devices (sound cards, video cards, etc.) to programs such as WinZip, which stores the names of recently opened files, the registry is essential for system functionality.
2. Registry Utilities and Keys
- HKEY_CLASSES_ROOT (HKCR): Contains
Understanding Linux Processes, Signals, and Commands
Understanding Linux Processes
A program is a set of instructions and data stored in a file. When loaded into memory to run, it becomes a process. The operating system assigns resources (memory, processor, I/O) to each process for execution.
Every process has a unique identifying number assigned by the kernel, called the Process ID (PID). Processes also have a Parent PID (PPID) identifying the parent process, and a Group ID for related processes.
Process States
Running: On single-processor machines,
Read MoreComputer Network Components and Protocols: A Comprehensive Guide
Computer Network Components
Hub
Collects all connections so that the failure of one does not affect the entire network. Two connection types: one for connecting stations and another for connecting with other hubs. Operates at the physical level of the OSI model. Does not analyze information, divide traffic, or disseminate information.
Bridge
Interconnects networks with different topologies and sub-network protocols. Operates at the link level of the OSI model with two different connectors, one for each
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