Three offices, three set-ups
A firm has a data team of 40, with one huge sales table. A call centre has 80 cheap screens, all showing the same live report. Two freelancers share a few spreadsheets from home.
You could build all three the same way. That would be wrong for at least two of them.
Key words
| Word | What it means |
|---|---|
| Client-server | a model where clients ask a central server for services |
| Thin client | a simple computer that does little itself and uses a server to run programs |
| Peer-to-peer | a model where every computer is both client and server, with no central server |
| Client | a computer that asks for a service |
| Server | a computer that gives a service |
| Network | devices joined so they can share things |
| Single point of failure | one part that stops everything if it breaks |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can describe three network models and choose the right one for a place.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Client-server has a central server
In the client-server model, a server holds the files, the accounts and the services. Each client asks the server for what it needs. The server answers.
It suits most schools and firms. Control, security and backups are in one place.
Try it: a client asks, a server answers
sales = ["Mon 120", "Tue 95", "Wed 143"]
def server(request):
if request == "all":
return sales
if request == "count":
return len(sales)
return "No such request"
print(server("count"))
print(server("all"))
print(server("delete"))
# Add "Thu 110" to the list. Ask for the count again.A thin client leaves work to a server
A thin client is a small, cheap computer with little processing power and little storage. The programs run on a strong server. The thin client only shows the screen and takes the keys.
It is cheap to buy and run. Updates are done once, on the server. Data stays on the server, which is safer. But if the network or server is down, the thin client does nothing.
Peer-to-peer has no central server
In a peer-to-peer network, every computer is both a client and a server. Each shares its own files with the others. There is nothing to buy but the computers.
It suits a tiny group, such as two freelancers. But nobody controls security or backups. Files end up scattered, and several copies of one data file may differ.
The three models compared
| Model | Benefits | Drawbacks | Suits |
|---|---|---|---|
| Client-server | Central control, security and backup. A strong server | Costs more. The server is a single point of failure. Needs a skilled person | Schools and firms |
| Thin client | Cheap clients. Easy updates. Data stays safe on the server | Needs a fast network and a strong server. Useless when the network is down | Call centres and labs |
| Peer-to-peer | Cheap and simple. No server to buy. No single point of failure | No central security or backup. Hard to manage as it grows | Tiny groups of a few computers |
The cells students fill in are left blank in this preview.