DEV Community: Vaishnavi Patil

Computer Networking

Vaishnavi Patil — Mon, 08 Aug 2022 11:11:08 +0000

Computer networking refers to interconnected computing devices that can exchange data and share resources with each other. These networked devices use a system of rules, called communications protocols, to transmit information over physical or wireless technologies.

Computer Network Components

Computer networks components comprise both physical parts as well as the software required for installing computer networks, both at organizations and at home. The hardware components are the server, client, peer, transmission medium, and connecting devices.

types of computer networks?

Depending on the organization's size and requirements, there are three common types of enterprise private networks:

1.Local area network (LAN): It is a group of computers and peripheral devices that share a common communications line or wireless link to a server within a distinct geographic area.

2.Wide area networks (WAN): It is a geographically distributed private telecommunications network that interconnects multiple local area networks (LANs)

3.Prsonal area network (PAN): A PAN is most commonly used for one individual and to connect just a handful of devices such as a computer, smart phone, and printer.

4.Metropolitan area network (MAN): Larger than a LAN but smaller than a WAN, a MAN incorporates elements of both types of networks. Ownership and management can be handled by a single person, but it’s more likely done by a larger company or organization.

What is Network Protocols

A network protocol is an established set of rules that determine how data is transmitted between different devices in the same network. Network protocols are the reason you can easily communicate with people all over the world, and thus play a critical role in modern digital communications.

Types of network protocol

1.Transmission Control Protocol (TCP): TCP stands for Transmission Control Protocol a communications standard that enables application programs and computing devices to exchange messages over a network.

2.Internet Protocol (IP): Internet Protocol (IP) is the method or protocol by which data is sent from one computer to another on the internet.

3.User Datagram Protocol (UDP): What is UDP protocol used for?
User Datagram Protocol (UDP) refers to a protocol used for communication throughout the internet.

4.Post office Protocol (POP): POP3 is designed for receiving incoming E-mails.

5.Simple mail transport Protocol (SMTP): SMTP is designed to send and distribute outgoing E-Mail.

6.File Transfer Protocol (FTP): FTP allows users to transfer files from one machine to another.

7.Hyper Text Transfer Protocol (HTTP): Through the HTTP protocol, resources are exchanged between client devices and servers over the internet.

8.Hyper Text Transfer Protocol Secure (HTTPS): Hypertext Transfer Protocol Secure (HTTPS) is a protocol that secures communication and data transfer between a user's web browser and a website.

What is network topology?

The arrangement of nodes and links is called network topology. They can be configured in different ways to get different outcomes. Some types of network topologies are:

1.Bus topology
Each node is linked to one other node only. Data transmission over the network connections occurs in one direction.

2.Ring topology
Each node is linked to two other nodes, forming a ring. Data can flow bi-directionally. However,single node failure can bring down the entire network.

3.Star topology
A central server node is linked to multiple client network devices. This topology performs better as data doesn’t have to go through each node. It is also more reliable.

4.Mesh topology
Every node is connected to many other nodes. In a full mesh topology, every node is connected to every other node in the network.

What is a port?

A port is a virtual point where network connections start and end. Ports are software-based and managed by a computer's operating system. Each port is associated with a specific process or service.

There are different types of ports available:

1.Serial port
2.Parallel port
3.USB port
4.PS/2 port
5.VGA port
6.Modem port
7.FireWire Port
8.Sockets
9.Infrared Port
10.Game Port
11.Digital Video Interface(DVI) Port
12.Ethernet Port

What is OSI model?

OSI stands for Open System Interconnection is a reference model that describes how information from a software application in one computer moves through a physical medium to the software application in another computer.

OSI consists of seven-layer, each layer performs a particular network function:

Introduction to APIs

Vaishnavi Patil — Thu, 21 Jul 2022 11:18:05 +0000

API stands for Application Programming Interface.You may use APIs to request access to another server's resources or you may use your own APIs to automate certain tasks.A Browser API can extend the functionality of a web browser. A Server API can extend the functionality of a web server.

What is API used for in web development

API is the acronym for Application Programming Interface, which is a software intermediary that allows two applications to talk to each other. Each time you use an app like Facebook, send an instant message, or check the weather on your phone, you're using an API.

How to use an API?

The steps to implement a new API include:

Obtaining an API key. This is done by creating a verified account with the API provider.
Set up an HTTP API client. This tool allows you to structure API requests easily using the API keys received.
If you don’t have an API client, you can try to structure the request yourself in your browser by referring to the API documentation.
Once you are comfortable with the new API syntax, you can start using it in your code.

Types of API

There are 4 main types of APIs(Application Programming Interface) by availability/release policies-

1.Open APIs (Public APIs)- Publicly available to developers and other users with minimal restriction. They may require registration, use of an API Key or OAuth, or maybe completely open. They focus on external users, to access data or services.

2.Partner APIs- allows you as a partner to perform all the GET operations that you do in your partner store. partner API is built using REST principles. This ensures predicatable URLs that make it easy to write and retrieve data related to your partner store. This API follows HTTP rules.

3.Internal APIs (private APIs)- Provide access to sensitive resourses within an organization's software system. They simplify the process of linking back-end systems or data between the multitude of applications that control internal operations.

4.Composite APIs- Design approach to batch API requests sequentially into a single API call. Rather than multiple round trips to a server, a client can make one API request with a chain of calls and receive one response.

Different types of API Protocols

1.SOAP
2.REST
3.JSON-RPC
4.gRPC
5.GraphQL
6.XML-RPC
7.Apache Thrift

Difference between GraphQL and REST API

GraphQL

GraphQL is a query language and server-side runtime for application programming interfaces(APIs) that prioritizes giving clients exactly the data they request and no more. GraphQL is designed to make APIs fast, flexible, and developer-friendly.

Features of GraphQL

Here are important features of GraphQL:

It is statically typed, so you do not need to define variable before using it.
GraphQL can decouple frontend from backend.
No over or under fetching of data.
It is language and HTTP agnostic.
Documentation of GraqphQL comes with no extra cost.
It helps you to save bandwidth.

Fetching Remote Data

Assume that a mobile or web app wants to access data from a server that displays the blog author information. The app is supposed to display the author’s name, the blog posts written by the author, and the three most recent blog topics written by him/her. Let’s give an abstract level review on how to fetch this data in REST vs GraphQL.

fetch('https://learnwithjason.dev/graphql', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    query: `
        query GetLearnWithJasonEpisodes($now: DateTime!) {
          allEpisode(limit: 10, sort: {date: ASC}, where: {date: {gte: $now}}) {
            date
            title
            guest {
              name
              twitter
            }
            description
          }
        }
      `,
    variables: {
      now: new Date().toISOString(),
    },
  }),
})
  .then((res) => res.json())
  .then((result) => console.log(result));

GraphQL Query Request

In this post, we discussed how you can use HTTP GET and POST methods to send GraphQL requests. We also looked at some of the nuances and limitations of each approach.

Rest API

When a client request is made via a RESTful API, it transfers a representation of the state of the resource to the requester or endpoint. This information, or representation, is delivered in one of several formats via HTTP: JSON (Javascript Object Notation), HTML, XLT, Python, PHP, or plain text. JSON is the most generally popular file format to use because, despite its name, it’s language-agnostic, as well as readable by both humans and machines.

Fetching Remote Data

APIs consist of a set of data, that is often in JSON format with specified endpoints. When we access data from an API, we want to access specific endpoints within that API framework. We can also say that an API is a contractual agreement between two services over the shape of request and response. The code is just a byproduct. It also contains the terms of this data exchange.

In React, there are various ways we can consume REST APIs in our applications, these ways include using the JavaScript inbuilt fetch() method and Axios which is a promise-based HTTP client for the browser and Node.js.

fetch("/add", {
        method: "POST",
        headers: {
            Accept: "application/json",
            "Content-Type": "application/json"
        },
        body: JSON.stringify({
            a: parseInt(a),
            b: parseInt(b)
        })
    })
    .then(res => res.json())
    .then(data => {
        const {
            result
        } = data;
        document.querySelector(
            ".result"
        ).innerText = `The sum is: ${result}`;
    })
    .catch(err => console.log(err));

REST Request

REST requires that a client make a request to the server in order to retrieve or modify data on the server. A request generally consists of: an HTTP verb, which defines what kind of operation to perform. a header, which allows the client to pass along information about the request.