Understanding Multiplexers: Functionality and Applications
Multiplexers: Data Selection and Applications
A data multiplexer, or selector, is the electronic equivalent of a rotary switch. Input data is transferred through the contacts of the rotary switch. Similarly, with a multiplexer, input data is transferred through the selector circuit. The selection of data is achieved by mechanically rotating the rotor of the rotary switch. The data selector position is selected by applying the appropriate binary number for input data selection. A k data selector allows
Read MoreUnderstanding Computer Networks: Types, Advantages, and Protocols
Understanding Computer Networks
A computer network is a collection of interconnected computers that allows them to share resources (printers, disks, etc.) and information (programs and data).
Advantages of Using a Network
- Ability to share peripherals such as printers and fax machines.
- Ability to share information through databases.
- Elimination of scattered data on individual computers.
- Possibility of more comprehensive user control.
- Availability of faster and safer backups.
Types of Networks
Personal Area
Read MoreNetworking Essentials: VPNs, IPsec, NAT, and WAN Technologies
This document outlines key concepts related to Virtual Private Networks (VPNs), IPsec, Network Address Translation (NAT), and various Wide Area Network (WAN) technologies.
Key Concepts and Technologies
- IPsec: An industry-wide standard suite for securing IP communications.
- VPN: The creation of private networks across the Internet, ensuring secure data transmission.
- DSL: Uses ATM (Asynchronous Transfer Mode) as the Data Link layer protocol.
- CSU/DSU: Supplied when a router is connected to a Frame Relay
Computer Networking and Security Quiz
Modules 8 and 9: Networking and Security
Multiple Choice:
1. A basic computer network can be described as:
- A. A minimum of five computers linked together.
- B. Computer and cables that link the network together.
- C. Two or more computers that are linked together.
- D. The use of satellites linking computers together.
2. LAN stands for:
- A. Local area nodes.
- B. Logical arrangement of networks.
- C. Local area network.
- D. Linked-area network.
3. The primary difference between a LAN and a WAN is:
- A. The number of software
PHP, JavaScript, and jQuery: Key Concepts
Associative Arrays in PHP
Associative arrays use named keys instead of index numbers. Here’s an example of a two-dimensional associative array:
$students = array(
"John" => array("age" => 20, "grade" => "A"),
"Jane" => array("age" => 22, "grade" => "B")
);
foreach ($students as $name => $details) {
echo "$name: Age - " . $details["age"] . ", Grade - " . $details["grade"] . "<br>";
}Sessions and Cookies in PHP
Session: A way to store data across multiple pages securely
Read MoreUnderstanding RAM: Types and Uses
What is RAM (Random Access Memory)?
RAM (Random Access Memory) is a type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers.
Two Basic Types of RAM
There are two main types of RAM:
- DRAM (Dynamic RAM): Needs to be refreshed thousands of times per second.
- SRAM (Static RAM): Does not need to be refreshed as often, making it faster but