I have researched but nothing gives me a clear answer, even dummies.com was very unclear. Don't think me dumb (cause I'm not), but here are a few questions:

1. What exactly is an LAN? How is it set up?
2. How are proxies set up? Through the router or a computer?
3. How do businesses and schools make all their computers so you have to log onto the business network and you can save documents to the business server instead of the computer itself?

Thanks! A very concise answer would be appreciated.

A LAN is a local area network. I think it might be rather vaguely defined. For example, I have three computers in my room, which are all plugged into an 8-port network switch via Ethernet cables. The switch is then plugged into an Ethernet socket in the wall which provides my Internet access. The switch intelligently routes network packets so that they get to the destination computer (the details of which are quite interesting). You could say that my setup constitutes a small LAN; equally, you could say that the whole university campus is a sort of LAN (although that's less true, because I think a LAN might imply that all the computers can talk to each other, which isn't always possible with our setup). A LAN at your school is essentially a bunch of network switches connecting all the computers together. You also need some other stuff, like a router/DHCP server to make everything work properly (again, details quite interesting).

A more helpful distinction might be made with a WAN, like the public internet. If our computers were on the same LAN, I could connect to yours directly. But right now, I'm sitting on my own LAN behind a NAT, which hides the fact that there are however many computers on this LAN by making them all look like one computer (ie. have a single public IP address). it does this by transforming the network packets. All of your traffic to the internet goes through the NAT, and then replies from Scratch (for example) come back the same way, with the NAT transforming them again so that they go to your specific computer on the LAN.

A proxy is just a program that forwards requests on behalf of a client. For example, yesterday I plugged my Raspberry Pi into the network switch, but it couldn't get Internet access (because they do MAC address filtering; you have to register computers that you plug in before they let you online). So I ran a proxy (polipo) on my other computer, setup the Pi to use it as a proxy, and then I could download things. If you had a very clever router you might be able to run it on that, but as you know, all of this stuff is really just software. A wireless broadband router is just a fancy box with a computer in it programmed to do particular things.

3 is more complicated, and pretty application-specific. It depends whether you're using Windows or Mac or Linux, and that sort of thing, and the answers are less interesting.

Does that help any? Feel free to say no, and I'll give a different explanation.

EDIT: I just realised you said “concise”. Also, I'm not sure whether those questions would really count as Computer Science, but you'd have to take Brian up on that point.

DISCLAIMER: I could well be using terminology wrong, so check my definitions

That helped Blob! Not really sure how it isn't computer science, though. So is being on an LAN basically being connected to the same router?

turkey3_test wrote:

So is being on an LAN basically being connected to the same router?

I guess that's how I see it, yeah.

LAN can also be ad-hoc, but that's confusing as to how they work

Networking is like an onion and has many layers. The internet protocol (IP) on which the internet is based is not the lowest level and is why the internet runs over wires or fibre and across different types of WAN/LAN. A typical LAN nowadays is Ethernet. Computers can run protocols on top of Ethernet that are IP based or not IP based, so it can get confusing.

blob8108 gave a pretty good answer. And anything related to computers is pretty much Computer Science.

3. How do businesses and schools make all their computers so you have to log onto the business network and you can save documents to the business server instead of the computer itself?

There are many ways that it can be done. For the wifi, they would redirect all requests to their website asking the user to log in, once the user has logged in then it allows them to access other websites.

For school computers (there are multiple ways, but do similar things), they have all the computers connect to a specific server (Google-able) which has all the student and faculty accounts stored on it. So when you type in your username and password it sends those to the server to see if the credentials are correct, if they are, it allows the person onto the account. To store data and files, they all sync their data to a specific server (like Dropbox) that way you can access it from other computers. They may also have a shared drive (have you ever been able to go on your computer then transfer a file to another computer without using a flashdrive? It's basically like that).

Something my school uses is Citrix. All the students hate it, but it works. Novell also has something similar to it as well. Ubuntu has a built in feature that allows you to login remotely to a computer (or server, not exactly sure how it's done) called “Universal Client Configuration Service” which can do something similar to Citrix and Novell's product. But as blob8108 said, there are many ways that are all also very different.

Magnie wrote:

blob8108 gave a pretty good answer. And anything related to computers is pretty much Computer Science.

3. How do businesses and schools make all their computers so you have to log onto the business network and you can save documents to the business server instead of the computer itself?

There are many ways that it can be done. For the wifi, they would redirect all requests to their website asking the user to log in, once the user has logged in then it allows them to access other websites.

For school computers (there are multiple ways, but do similar things), they have all the computers connect to a specific server (Google-able) which has all the student and faculty accounts stored on it. So when you type in your username and password it sends those to the server to see if the credentials are correct, if they are, it allows the person onto the account. To store data and files, they all sync their data to a specific server (like Dropbox) that way you can access it from other computers. They may also have a shared drive (have you ever been able to go on your computer then transfer a file to another computer without using a flashdrive? It's basically like that).

Something my school uses is Citrix. All the students hate it, but it works. Novell also has something similar to it as well. Ubuntu has a built in feature that allows you to login remotely to a computer (or server, not exactly sure how it's done) called “Universal Client Configuration Service” which can do something similar to Citrix and Novell's product. But as blob8108 said, there are many ways that are all also very different.

My school (and probably the whole state. I'm not sure about the rest of the country. I am in Australia.) uses a proxy server to log in to the internet via both Ethernet and Wi-Fi to block websites and allow us to access our emails. The desktop computers used to have Novell (which looks very much like Windows, but is based on UNIX i think) but they updated them to Windows a few years ago and use Windows Server to log in.
I have used a few public Wi-Fi networks that use a web based login, but they are a lot slower than the school proxy log in.

^ My school uses the Apple server tools for accounts, and Dansguard for filtering. Not sure what for proxy tools.

Any apps? I want my home pc to be able to acsess all of my pcs. (I have a need for my dads bissmess)

QuillzToxic wrote:

Any apps? I want my home pc to be able to acsess all of my pcs. (I have a need for my dads bissmess)

I would suggest setting up a VPN.