Networks
About routers, switches, hubs, servers, clients and NIC's
OSI Model
OSI Model
7) Application layer
6) Presentation layer
5) Session layer
4) Transport layer
3) Network layer
2) Data link layer
1) Physical layer
I'm going to delegate to the wikipedia page: http://en.wikipedia.org/wiki/OSI_model, so you can understand what each layer individually does.
NICs
NIC
Example of use:
Use in PCs to connect to the internet.
Hub
Hub
Example of use:
Used in a cheap token network.
Switch
Switch
Example of use:
Used in a more expensive token network.
Router
Router
Example of use:
Connecting to your ISP with a modem.
Server
Server
Example of use:
Used in a star topology.
Client
Client
Fat client - this uses local storage and local CPU power
Hybrid client - this uses local CPU power but relies on server storage
Thin client - this relies on the CPU and the storage of data on the server
An example of a Fat client, or a rich client, is a computer running a CAD program, which then shares its work over the network.
An example of a Hybrid client is a computer running a game. This relies on the storage from the server, but does local processing.
An example of a Thin client is a web based email client. This client sends a request to the server, which then responds with the needed data. This also stores emails in this case, and the client only does minimal processing, like displaying graphics and sending data.
Example of use:
Used in all topologies.
Star Topology
Star topology
Pros:
Efficient
Can safely remove individual computers without the network crashing
Cons:
If the main server fails, the whole network fails
Example of use:
Organisations, schools etc.
Token ring topology
Token ring topology
Pros:
If one computer fails and the switch has an auto-short mechanism; the network can continue without it.
Less expensive.
Cons:
The data may not take the most direct route to the destination node, meaning that efficiency and speed is decreased.
Example of use:
Local home networks (not as widely used).
Bus topology
Bus topology
Pros:
Easily remove clients.
Cons:
Whole network breaks if the central bus breaks.
Example of use:
Not very widely used now (outdated).