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Client server architecture.

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Now, besides the many features that they have, the computers on a network, let's say Internet or

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Internet, can accomplish two basic actions.

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OK.

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Requesting and responding.

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So these two actions can define the role of a single computer on the network.

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The computers, which request their named clients, the ones which respond, are named servers, so

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typically computers on a network can have both roles as well.

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So basically a Web application works on a client server architecture.

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OK, so now first let's grapple with how the architecture works.

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The client requests some resources on the server to use and the server produces an appropriate output

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to respond to this request.

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The basic communication between the client, the server works like that.

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Now, today with HTP two, there are some changes in this type of communication.

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But again, this isn't necessarily the topic of this course.

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So anyway, now let's have a look at how clients and servers are shaped in a basic network.

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So a client is a computer that makes requests to a server, right?

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In fact, we don't necessarily have to limit a client to a computer only.

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Because clients can come up in different shapes and sizes such as your smartphone, laptop, PC and

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so on.

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Now, also, a piece of software on your computer can be a client, which is requesting yeah, so generally

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in a penetration test, the client will mean your Web browser and Web browsers are the first point to

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reach a Web application.

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And we're going to dig a little deeper into Web browsers and some of the coming sections.

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Now, on the other hand, a server is a computer that responds to the request of the client, so servers

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likewise come up in many shapes and sizes.

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A server is both a piece of hardware, the computer itself, as well as a piece of software.

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So that means that there are several different types of servers do what and how they serve, some of

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them are Web servers, some of them are database servers.

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There's file servers and mail service.

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Now, in the real world, a server has a faster CPU, higher capacity of RAM and storage and so on,

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many more features than you know, it makes that more resilient than a client.

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Although a simple computer can also be a server.

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Now, the client server relationship begins when you request a Web page through your favorite Web browser.

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So at this point, your computer or your Web browser is a client and the computer is sending you the

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response is the server.

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So when you type NBA dotcom into the address bar and hit enter, the communication between the browser

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and the NBA server will start.

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Now, from this pain below, you can observe the requests.

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And to be able to display the page properly, the browser requests many resources from the server,

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such as the email documents, stylesheet scripts and many more.

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You can also display details about the request and responses from this pain.

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But again, this is a topic for another video, or you can just look around.

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So now let's open another layer so that we can understand the basics of Web applications.