Computer Networks

Worms are self-replicating programs that can spread across computer networks automatically by exploiting vulnerabilities, without needing any human action like opening an attachment. In contrast, computer viruses typically require human involvement, such as running an infected program, to spread. This independence makes worms particularly dangerous for network security.

An intranet is a private, secure network that is accessible only to authorized members or employees within a specific organization. It is used to share information, collaboration tools, and operational systems securely. In contrast, the Internet is public, and LAN or WAN refer to the geographical scale of networks rather than their private access restrictions.

The Internet is the ultimate example of a Wide Area Network (WAN) because it connects millions of computers and smaller networks globally across vast geographical distances. A Local Area Network (LAN) is restricted to a small area like a single building, and a Metropolitan Area Network (MAN) covers a city. RAM is a type of computer memory, not a network type.

The cloud refers to servers accessed over the internet, along with the databases and software that run on those servers. LAN, WAN, and MAN are types of physical network infrastructures (Local, Wide, and Metropolitan Area Networks) rather than the services hosting files and information.

A hub is a basic networking device that connects multiple computers or devices together in a local area network (LAN), broadcasting data to all connected ports. While routers connect different networks together and modems connect a network to the internet, a hub specifically serves as a common connection point for devices in a single network.

Fibre optics involve the transmission of information as light pulses through physical glass or plastic strands, making it a form of wired (or cabled) communication. Radio waves, Bluetooth, and 4G are all wireless technologies that transmit data through the air without physical cables.

Network forensics is a sub-branch of digital forensics that specifically deals with the monitoring and analysis of network traffic to gather evidence or detect security incidents. It focuses on data in transit across a network rather than data stored on individual local devices.

A Distributed Denial of Service (DDoS) attack uses a network of multiple compromised systems (a botnet) to flood a target website or server with traffic, causing it to crash or become unavailable to legitimate users. SQL is a database language, while USB and WLAN are hardware/networking standards.

Data transmitted over a network is broken down into small, manageable units called packets, which are routed individually and reassembled at the destination. Bytes and nibbles are units of data storage size, not the transmission units used by network protocols.

The internet is a global system of interconnected computer networks, which classifies it as a Wide Area Network (WAN). LANs are typically restricted to smaller geographic areas like a building or home.

Every network topology or design involves trade-offs. Therefore, all types of networks inherently possess both advantages and disadvantages depending on the specific use case.

In a star network, each node is connected to a central hub or switch. Because each device has its own dedicated cable to the central point, data collisions are effectively eliminated compared to bus topologies.

Star networks are generally considered reliable because a failure in one cable only affects the connected device, not the whole network. However, they are more expensive to install due to the amount of cabling and the need for a central hub.

A bus network uses a single central cable, known as a backbone or trunk, to which all devices are connected. If this backbone cable fails, the entire network goes down.

Ring networks are often cited for being relatively easy to install and configure compared to more complex topologies, as each device is simply connected to two others in a closed loop.