Question

Define the following terms: a. HTTP. b. Multitier application. c. Request method.

Short answer

HTTP is a protocol for web communication. A multitier application separates functions into layers. Request methods in HTTP specify actions on resources.

Step-by-step solution

Define HTTP

HTTP stands for Hypertext Transfer Protocol. It is the foundational protocol used by the World Wide Web to define how messages are formatted and transmitted, and how web servers and browsers should respond to various commands.

Define Multitier Application

A multitier application is a software architecture pattern that separates applications into different layers. Each tier or layer serves a specific function, such as presentation, business logic, or data management, allowing for improved scalability, maintainability, and manageability.

Define Request Method

A request method is a component of HTTP used to define the desired action that should be performed on a given resource. Common request methods include GET, POST, PUT, DELETE, among others, each serving specific purposes such as retrieving data or submitting data to be processed.

Key concepts

HTTP (Hypertext Transfer Protocol)

The Hypertext Transfer Protocol, or HTTP, is the backbone of data communication for the World Wide Web. It's a protocol that dictates how messages are exchanged between web browsers and servers. HTTP was specifically designed to facilitate hypermedia information systems. This means it allows the fetching of resources, such as HTML documents, to be rendered by the browser, which the user can then view or interact with.

HTTP is a stateless protocol. This means that each request from a client to a server is treated as an independent transaction, with no memory of previous interactions. As a result, HTTP is efficient, because it does not carry the overhead of retaining session information. However, it requires supplementary technologies, like cookies or sessions, to maintain a user's state across multiple HTTP interactions.

• It operates at the application layer of the OSI model.
• HTTP/S adds a layer of security by using encryption.
• It's been successively updated to improve on earlier versions, with HTTP/2 and HTTP/3 offering improved performance and security features.

Multitier Applications

Multitier applications, also known as n-tier applications, are architectural models that divide the app's functions into layers or "tiers." This segregation optimizes the application by allowing different services to run independently.

There are generally three main tiers in a multitier application:

• Presentation Tier: This is the user interface, or the front-end, where users interact with the application.
• Business Logic Tier: Often considered the "brains" of the application, this layer processes data between the presentation and the data store.
• Data Tier: This tier stores and manages data. It interacts with the business logic layer to retrieve, store, or manipulate data as needed.

Each tier operates independently, allowing developers to manage and update applications with ease without affecting other tiers. This makes multitier architecture highly scalable and maintainable as applications grow in complexity.

Request Methods

Request methods are fundamental components of HTTP used to specify what actions should be carried out on a resource. The choice of request method influences both how a server processes a request and how the application behaves.

Here are some common HTTP request methods:

• GET: Used to request data from a specified resource. It should not have any effect on the data on the server.
• POST: Submits data to be processed to a specified resource, often causing a change in state or side effects on the server.
• PUT: Uploads a representation of the specified resource, effectively modifying it or creating it if it does not already exist.
• DELETE: Removes the specified resource.

Each request method serves a specific purpose, ensuring that data is handled correctly during web interactions. Understanding these methods is crucial for web development, as they dictate how web clients and servers communicate in a standardized manner.