Define a network
Two or more computers connected together, to share information and resources
Define a LAN
Local Area Network:
A connection of devices
In a small geographical location
What are the advantages of a LAN?
- Enables privacy from the outside world
- Can control the access to data/programs
- Can control the access to devices
What are the disadvantages of a LAN?
- Requires some expertise to install and maintain
- Can be costly for a larger LAN
- Unauthorised access to data depends on personnel and their security measures
Describe the role of an NIC
Network Interface Card:
Converts data signals from a node into one that can be transferred over a network
Describe the role of a switch
Connects all the nodes together; intelligent so can send data packets only to their intended destination
Describe the role of a hub
Connects all the nodes together; not intelligent so data packets are transmitted across the whole network
Describe the role of a router
Manage data packets, enabling them to be sent between networks
Describe the role of a WAP
Wireless Access Point:
Allows nodes to connect to the network wirelessly
What is the difference of a client-server network over a peer-to-peer network?
- A computer is designated as the server, rather than all having the same status
- Server manages network traffic and data requirements, thus having less collisions and being faster
- Larger networks have more servers, this can handle a greater network demand
- Popular of companies, rather than home networks
Advantages and disadvantages of a bus network topology
- Cheap, due to all nodes being connected to one cable
- Data collisions slow the network - travels both ways
- Whole network suffers from cable faults
- Only useful over small areas
Advantages and disadvantages of a ring network topology
- Cheap: only one cable
- One-way data travel - no collisions
- Whole network suffers from cable faults
Advantages and disadvantages of a star network topology
- Other nodes are unaffected from a cable fault
- Can be costly with large number of nodes
- Network will slow with multiple nodes requesting data or software at the same time
Advantages and disadvantages of a mesh network topology
- Every node is connected
- Other routes are available to combat high network traffic or cable faults
- Very expensive: large amounts of cabling required
What is the difference between a LAN and a WAN?
LAN: Located on one site, owner owns the network devices
WAN: Covers a large geographical area, devices can be provided by telecoms companies
Explain 'Web Hosting'
A computer on a network: serves users of the internet as a host.
Websites are usually hosted on servers for people to access them (sometimes for a fee)
Explain 'IP address'
Internet Protocol Address:
A unique number given to every computer on the internet.
Identifies the computer, may change each time a network is joined
Internet Service Provider:
The company who provides you with an internet connection
Uniform Resource Locator:
The name for a web adress
Domain Name System:
The system used to find the computer hosting the required website
Explain 'the Cloud'
A network of servers hosted on the internet, offering a range of services for data
How does a DNS work?
- The website's URL is entered
- The URL is sent to the ISP, where it is looked up in their DNS's address book
- The required IP address is returned to you, to communicate to the computer hosting the website
Advantages of the Cloud
- Don't need to buy and install software
- Any connected device can access the service
- No need to upgrade software
- Collaborative documents can be formed
- Work is saved automatically
Disadvantages of the Cloud
- Sensitive data stored in other countries may be under different data laws
- Can be less secure than local storage
- Completely reliant upon the network/internet
What is the role of an internet registrar?
- Holds the details of domains available for purchase
- Registers company details
- Resolves domain name disputes
How are files sent over the internet?
They are split into data packets before being transmitted
What are the components of a data packet?
Describe the Error check within a data packet
Includes a checksum number: a calculation for checking if all the data has arrived uncorrupted
Describe the Packet header within a data packet
Sequence number: for data packets to be put back together in the right order
Return address: when needed to notify the sender's computer if the packet has been received or has been corrupted
Destination address: so the packet arrives in the correct location
Define a protocol
A set of rules for devices to follow