HTTP request / response
Clients are devices that display HTML documents. These can be desktop, laptop computers, or smartphones.
Servers are the devices that contain the information. Servers can be of a different performance, depending on how busy network traffic is. If network traffic is so busy, than more than one server may be used.
Different types of network: LAN, MAN, WAN, Internet
Networks can be of different sizes. Smallest of them all is LAN. LAN stands for Local Area Network. It is contained in a single building or nearby buildings.
A larger one is MAN - metropolitan area network. It covers network located in a single city. Personally I never had a chance to see one.
WAN stands for Wide Area Network, when computing resources are located in different geographical locations.
The largest network is Internet. You are reading this article browsing the Internet.
When a request is made on the Internet it is usually of two types HTTP or HTTPS. S in HTTPS stands for secure. I say usually, because there are additional protocols out there, in this article I will not cover them all.
HTTP(s) request will indicate what type of information needs to be accessed.
Protocol is something that reminds us of a judicial system. Protocol is a set of rules that needs to be used. Common Internet protocols are HTTP and HTTPS.
Domain indicates where the information will be coming from. If it is a local network, than server name can be used. If we are talking about Internet, than domain name is not a physical machine, but a one or more servers serving the traffic. I am saying one, because if it is a startup or traffic is low, than one server may be used. It is not a good idea to use a single server for redundancy reasons. If it is a larger company, than more than one server is needed to serve the traffic.
Document - this is optional. By default request will pull default document of the web site, if the web site consist of more than one page, than document will indicate, which information needs to be displayed.
Single URL may display a lot files at once. For example a web page may contain images, even so a single request for a web page was made, this page may include additional files. A separate request will be made to access that information.
Understanding Network Basics
Quiz
What is the primary function of a client device in the context of network communication, and what are some common examples of client devices?
Describe the role of servers in a network. Why might a network utilize more than one server?
Briefly define LAN, and provide a typical geographical scope for this type of network.
What does MAN stand for, and what is its distinguishing characteristic in terms of network size?
Explain what a WAN is, highlighting the key difference between a WAN and a LAN.
What is the Internet, and how does it relate to other types of networks discussed?
What is the primary difference between HTTP and HTTPS, and what does the "S" in HTTPS signify?
Define the term "protocol" in the context of internet communication, and provide two examples of common internet protocols mentioned in the text.
Explain the function of a "domain" in an internet request. How does its role differ in a local network versus the internet?
What is the purpose of the "document" part of a network request, and what happens if it is not specified in the request?
Answer Key
Client devices are used to display HTML documents received from servers. Common examples include desktop computers, laptop computers, and smartphones.
Servers are devices that store and provide information in a network. Multiple servers may be used to handle busy network traffic and for redundancy.
LAN stands for Local Area Network. It is a network contained within a single building or nearby buildings.
MAN stands for Metropolitan Area Network. It covers a network located within a single city.
A WAN, or Wide Area Network, connects computing resources located in different geographical locations, unlike a LAN which is geographically limited.
The Internet is the largest network, connecting numerous networks globally. The article mentions that browsing the Internet is a common way to interact with it.
The primary difference is security. HTTPS includes a secure layer for transmitting data, indicated by the "S," while HTTP does not offer this inherent security.
A protocol is a set of rules that needs to be followed for communication. Common Internet protocols mentioned are HTTP and HTTPS.
The domain indicates the source of the information. In a local network, it can be a server name, while on the Internet, a domain name represents one or more servers.
The "document" part of a request specifies which particular information or webpage needs to be displayed on a website with multiple pages. If not specified, the default document of the website is typically pulled.
Essay Format Questions
Compare and contrast the different types of networks discussed in the text (LAN, MAN, WAN, Internet), focusing on their scale, geographical scope, and potential applications.
Discuss the roles of clients and servers in network communication. Explain how they interact to enable users to access information on the internet.
Explain the significance of protocols in internet communication, using HTTP and HTTPS as examples. Why is the distinction between them important for online security?
Analyze the components of a typical internet request (protocol, domain, document). How does each component contribute to locating and retrieving information on the internet?
Discuss the reasons why a website or online service might utilize multiple servers. What are the benefits of such an infrastructure in terms of performance and reliability?
Glossary of Key Terms
Client: A device that requests and displays information, typically HTML documents, from a server. Examples include computers and smartphones.
Server: A device that stores and provides information or resources to client devices over a network.
LAN (Local Area Network): A network that connects devices within a limited geographical area, such as a single building or nearby buildings.
MAN (Metropolitan Area Network): A network that covers a larger geographical area than a LAN, typically within a single city.
WAN (Wide Area Network): A network that connects devices across different geographical locations, often spanning cities, states, or countries.
Internet: The largest global network, connecting numerous smaller networks together.
HTTP (Hypertext Transfer Protocol): A common protocol used for transmitting files (such as web pages) on the World Wide Web.
HTTPS (Hypertext Transfer Protocol Secure): A secure version of HTTP that encrypts the communication between the client and the server.
Protocol: A set of rules and procedures that govern how data is transmitted and received over a network.
Domain: An identification string that defines a realm of administrative autonomy, authority or control within the Internet. In the context of a web request, it indicates where the information is coming from.
Document: A specific file or resource requested from a server, often a webpage within a website. If not specified, the server may provide a default document.
FAQs
What are clients and servers in the context of accessing information on a network?
Clients are devices, such as desktop computers, laptops, or smartphones, that are used to display HTML documents. Servers are devices that store the information being accessed. The performance and number of servers can vary depending on the volume of network traffic.
What are the different types of networks, and how do they differ in geographical scope?
Networks can be categorized by their size and geographical reach. A Local Area Network (LAN) is the smallest, typically confined to a single building or nearby buildings. A Metropolitan Area Network (MAN) covers a single city. A Wide Area Network (WAN) connects computing resources across different geographical locations. The largest network is the Internet, which is a global network connecting countless devices and networks.
What is the significance of HTTP and HTTPS when making a request on the internet?
HTTP (Hypertext Transfer Protocol) and HTTPS (Hypertext Transfer Protocol Secure) are common protocols used for making requests on the internet. An HTTP(s) request indicates the type of information being requested. The 'S' in HTTPS signifies a secure connection, implying that the communication is encrypted for added security. These protocols are sets of rules that govern how data is transmitted over the internet.
What role does a domain play in accessing information online?
A domain indicates the source of the information being requested. On a local network, a server name might suffice. However, on the internet, a domain name represents one or more servers that handle the traffic. While a small website or startup might use a single server, larger organizations typically employ multiple servers for redundancy and to manage higher traffic volumes.
What is a document in the context of a URL, and is it always required?
In a Uniform Resource Locator (URL), the document part is optional. It specifies a particular resource or page to be accessed on a website. If no document is specified, the request will typically retrieve the default document or homepage of the website.
How does a single request for a webpage potentially lead to multiple file retrievals?
Although a user might make a single HTTP(s) request to view a webpage, that page can contain references to various other files, such as images. When the browser receives the initial HTML document, it parses it and then makes separate, additional requests to the server to retrieve these embedded files so that the entire webpage can be displayed correctly.
What is a protocol in the context of internet communication?
A protocol, in the context of internet communication, is a set of rules that must be followed for devices to communicate effectively. It ensures that data is formatted, transmitted, and interpreted correctly by both the client and the server. Common internet protocols include HTTP and HTTPS, which define the standards for requesting and delivering web content.
How does the concept of redundancy relate to the number of servers a website might use?
Redundancy is a key consideration when determining the number of servers a website utilizes, especially for larger companies with significant traffic. Using multiple servers ensures that if one server fails, others can continue to serve traffic, preventing website downtime and ensuring continuous availability of information. This is why relying on a single server, particularly for a heavily accessed website, is generally not a recommended practice.
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