Friday 3 June 2022

Difference between AWS Security Groups and NACLs

What are the differences between AWS Security Group and NACLs (Network Access Control List)?

Security Group NACL

Security Groups: A security group in AWS act as a virtual firewall which controls the traffic that is allowed to reach or leave the associated resources.

The main characteristics of a security group are as listed below:

1. Security group operates at the instance level

2. This is stateful: return traffic is automatically allowed, once the incoming traffic is already trusted

3. All rules are evaluated every time before deciding whether to allow the traffic

4. It supports allow rules only

5. Applies to an EC2 instance, only when someone do it manually


NACL (Network Access Control List): A network access control list (NACL) in AWS act as an additional layer of security that controls traffic (in and out) at VPC level for one or more subnets associated with the respective VPC (Virtual Private Cloud).

The main characteristics of a NACL are as listed below:

1. NACL operates at the subnet level

2. This is stateless: return traffic must be explicitly allowed by rules else the return traffic will be denied

3. Rules are evaluated in order (lowest to highest) when deciding whether to allow traffic, the lowest number has the highest priority

4. It supports both allow and deny rules

5. It applies automatically to all EC2 instances in the subnet associated with the respective VPC


Cheers! Write me back if you have any queries or feedback.

Tuesday 10 May 2022

Web Development

Web development: - Web development define as creating, building, and maintaining websites. It includes aspects such as web design, web publishing, web programming, and database management. It is the creation of an application that works over the internet i.e. websites.

Web development is classified into two categories.

Frontend development: - The frontend developer builds the front part of the website and the applications that the user interacts with directly are termed as front-end. It is also referred to as the client-side of the websites/application.

For building the front end portion use the following language: - 

·      HTML: - HTML stands for Hypertext Markup Language. It is the code that is used to structure a web page and its content. HTML code ensures the proper formatting of text and images for your Internet browser. Without HTML, a browser would not know how to display text as elements or load images or other elements. HTML also provides a basic structure of the page.

·     CSS: - CSS stands for Cascading Style Sheets. CSS is a style sheet language used for describing the presentation of a document written in a Markup language such as HTML.

·    JavaScript: - JavaScript is the world’s most popular programming language. JavaScript is used by programmers across the world to create dynamic and interactive web content like applications and browsers.

Backend Development: - The backend is defined as parts of a computer application or a program’s code that allow it to operate and that cannot be accessed by a user. Most data and operating syntax are stored and accessed in the back end of a computer system.

For building the Back end portion use the following language: -

·    Python: - Python is the most popular language that lets you work quickly and integrate systems more efficiently.

·    Ruby: - Ruby is mostly used for building a web application. It is dynamic, reflective, object-oriented, and a general-purpose language. Ruby is a pure Object-Oriented language developed by Yukihiro Matsumoto.

·   PHP: - PHP is a server scripting language, and a powerful tool for making dynamic and interactive Web pages. it is a widely-used, free, and efficient alternative to competitors such as Microsoft's ASP.

·    Node.js: - Node.js is a cross-platform, open-source server environment for executing JavaScript code outside a browser.

·  DBMS: - DBMS stands for Database Management System. It is software that is used to manage the database. 

Saturday 7 May 2022

What is EC2 instance in AWS Cloud?

 What is Amazon EC2 in AWS Cloud?

Amazon EC2 stands for Amazon Elastic Compute Cloud which offers various types EC2 instances to run your workload. An Amazon EC2 instance in AWS is a cloud based Virtual Machine where you install and run your applications/services. This is one of the most popular offering of AWS Cloud, and this is part of Infrastructure as a service on AWS.

There are various types of instances types that Amazon EC2 offers (e.g. General Purpose, Compute Optimized, Memory Optimized, Storage Optimized etc...), each Instance types can have various families (e.g. Mac, T4g, T2, T3 M5 etc..), and each families may have various instances sizes that allows you to choose the right capacity of the EC2 instance to run your workload as per the business requirement.

Unlike traditional virtual machines, the computing capacity of EC2 instances are scalable without investing in buying additional capacity of hardware. This is one of the major advantage of EC2 instances which makes it easily adoptable for almost all business type users or consumers.

Cheers! Please write me back if you have any queries or suggestions.

Wednesday 4 May 2022

Introduction to Web Technology

Web technologies define the way computers communicate with each other using markup languages. It communicates across the web and creates, delivers, or manages web content using a hypertext markup language (HTML).

Web technology can classify into the following terminology.

·       World Wide Web (WWW): - World Wide Web is a Hypertext-based information system like a Web browser, Hypertext markup language (HTML), and Hypertext Transfer Protocol (HTTP).

·       Web page: - A Webpage is a digital document that is linked to the World Wide Web and displayed on a web browser such as Google Chrome, Firefox, Opera, and safari.

·       Web Browser: - A Web browser takes you anywhere on the internet. It is a software application to explore the WWW (World Wide Web). And it also provides an interface between the server and the client and requests the server for the web document and services.

·       Web server: - A web server is important for running websites on a computer. It is a program that processes the network request of the user and serves them with files that create a web page.

·       Web development: - Web development refers to creating, building, and maintaining websites. It includes aspects such as web design, web publishing, web programming, and database management. It is the creation of an application that works over the internet i.e. websites.

·       URL: - URL stands for Uniform Resource Locator. A URL is an address of the given unique resource on the Web. each valid URL points to a unique resource. Such resources can be an HTML page, a CSS document, an image, etc.

·       Gateway: - The gateway is a method to Internet Service Provider that gives you access to the entire Internet. For a basic internet connection at home.

·       API: -  A web API is an Application Programming Interface for either a web server or a web browser.

·       XML: -  XML stands for Extensible Markup Language. It is a markup language such as HTML and is designed to store and transport data.


There are two types of webpages

Static webpage: - Static pages show the same content each time they are viewed. It is built using HTML code and features the same presentation and content, regardless of user identity or other factors.

o   Easy to build using HTML and CSS.

o   Cheap to host.

o   It has fixed content.

Dynamic webpage: - Dynamic pages have content that can change each time they are accessed. Or, A dynamic page displays different content for different users while retaining the same layout and design.

o   It is a built-in scripting language such as PHP, Perl, ASP, or JSP. The scripts in the pages run functions on the server that return things like the date and time, and database information.

o   It is a little hard to build.

o   Costly than static websites to host.

o   Easily edit the content on their own.