Essential Computer Science Concepts and IT Definitions
System Fundamentals
A system is a set of interrelated parts working together to achieve a common goal.
System Components
- Environment
- Inputs
- Process
- Outputs
Information Systems
An Information System (IS) is a set of elements and procedures designed to improve data processing and elaborate reports, facilitating decision-making to achieve beneficial goals.
Data Processing
Data Processing is a series of elementary operations performed on data to produce results.
Process Flow: Reception → Storage → Processing
Read MoreOperating System Fundamentals: Core Concepts & Components
Understanding Operating Systems
An operating system acts as an intermediary between a user of a computer and the computer hardware.
Scheduling Challenges
Scheduling involves managing machine time. For example, a user might sign up for an hour but finish their job in 45 minutes. This would result in wasted computer idle time. Conversely, a user might run into the problem of not finishing their job in the allotted time.
Operating System Types
- Serial Processing
- Batch Processing
- Multitasking or Time-Sharing
Understanding File System Structure and Operations
File System Structure
A file system structure typically consists of:
- Boot Block: Contains boot information.
- Super Block: Contains metadata about the file system.
- Inode Table: Contains inode structures for each file.
- Data Blocks: Store file data.
- Directory Blocks: Store directory information.
Key Components
- Inodes: Contain file metadata (ownership, permissions, location).
- File Descriptors: Identify open files.
- Directory Entries: Map file names to inodes.
File System Operations
- Create: Create a new file or directory.
Core Computer Concepts: Hardware, Software, Networking
Understanding Computers and Data
Computers are machines capable of processing information and performing many different operations. They come in various forms:
- Types of Computers:
- Personal Computers (PCs)
- Notebooks (Laptops)
- Servers
- Personal Digital Assistants (PDAs)
Data Measurement Units: Bits & Bytes
These units are used to measure the amount of information a device can hold.
- Bit: The minimum unit of information. It’s a binary digit (0 or 1).
- Byte: A fundamental unit consisting of 8 bits.
- Kilobyte (
Essential Operating System Principles
Process Control Block (PCB) Essentials
The Process Control Block (PCB) is a fundamental data structure maintained by the operating system for every process. It contains all the information needed to manage and control a process. The PCB is essential for process scheduling, context switching, and execution.
Key Components of a PCB
Here are the main components typically stored in a PCB:
- Process ID (PID): Unique identifier for the process.
- Process State: Current status (e.g., Ready, Running, Waiting, Terminated)
Database Concepts and Architectures Explained
Oracle Database Fundamentals
Oracle Memory Structures: SGA and PGA
The basic memory structures associated with Oracle are the System Global Area (SGA) and the Program Global Area (PGA). This statement is True.
Oracle Background Processes: LGWR and PMON
- LGWR: Log Writer
- PMON: Process Monitor
Single-User vs. Multi-User Databases
Single-User Database
A database that only one user can access at a time. It is mainly used for personal or small-scale applications where simultaneous data access by multiple users