🧠 What is EXISTS? EXISTS is a logical operator in SQL that checks whether a subquery returns any rows. It’s often used …

Here’s a comprehensive guide to Docker container commands with explanations and examples. I’ll organize them by category so it’s easy to reference. …

Here’s a comprehensive list of Docker commands related to images, broken down by category, with explanations and examples: 1. Pulling and Searching …

A Secret in Kubernetes is an object that stores sensitive information such as passwords, tokens, SSH keys, or certificates, separate from application …

A ConfigMap in Kubernetes is an API object used to store non-confidential configuration data in key-value pairs, so you can separate configuration …

A Kubernetes Ingress is an API object that manages external access to Services, typically HTTP and HTTPS traffic, providing routing, load balancing, …

A Service in Kubernetes is an abstraction that defines a stable network endpoint for accessing a set of Pods — even if …

A Deployment in Kubernetes is a higher-level controller that manages ReplicaSets and provides declarative updates for Pods and applications. In simpler terms …

A ReplicaSet (RS) in Kubernetes ensures that a specified number of identical Pods are running at any given time.It’s one of the …

A Pod is the smallest and simplest deployable unit in Kubernetes. It represents one or more containers that share the same network, …

🧱 1. Repository Setup Purpose: Start tracking a project with Git. Command Description Example git init Initialize a new Git repository in …

Let’s break down the difference between CrudRepository, PagingAndSortingRepository, and JpaRepository clearly — because they are related but not identical. 🧩 1. Common …

⚙️ 2. Creating Classes A class is a blueprint for creating objects. ✅ The constructor() runs automatically when you create a new …

🧩 1. What Is Destructuring? Destructuring means “unpacking” values from arrays or properties from objects into distinct variables. Instead of doing this: …

🧩 1. What Is Optional Chaining? Optional chaining (?.) lets you safely access nested object propertieswithout causing an error if something in …

Let’s go step-by-step through the Spread (...) and Rest (...) operators in modern JavaScript. 👇 🧠 What They Are Both use the …

In Vue 3, this concept is expressed using the createApp() function — it’s how you initialize and mount your application. 🧩 What …

🧩 1. What Are Modules? Modules allow you to split code into separate files and reuse functionality. Benefits: 🟢 2. Exporting 🔹 …

🧩 1. var 🔹 Example 🟢 2. let 🔹 Example 🔵 3. const 🔹 Example 🟣 4. Comparison Table Feature var let …

🧩 1. What is an Event Listener? An event listener is a function that waits for a specific event to happen on …

🧠 1. The Three Main Ways to Change Content Once you’ve selected an element, you can change its content using: Property Purpose …

1. What is async/await? async/await is a modern way to handle asynchronous code in JavaScript. It’s built on Promises but makes code …

1. What is a Promise? A Promise is an object that represents the eventual completion (or failure) of an asynchronous operation and …

🔐 ID Token in OpenID Connect (OIDC) Definition:An ID Token is a JSON Web Token (JWT) issued by an Identity Provider (IdP) …

🔐 OAuth 2.0 and OpenID Connect (OIDC) They’re closely related, but they serve different purposes: Protocol Purpose Summary OAuth 2.0 Authorization Lets …

🔐 What is SAML? Definition:SAML (Security Assertion Markup Language) is an open standard for Single Sign-On (SSO) that allows identity providers (IdPs) …

Definition:Identity and Access Management (IAM) is a framework of policies, processes, and technologies that ensures the right individuals (or machines) have the …

GraphQL is a query language and runtime for APIs, developed by Facebook (Meta) in 2012 and open-sourced in 2015.It provides a flexible …

Here’s a clear and concise list of the main HTTP status codes grouped by category, along with what they mean 👇 🟢 …

DDD stands for Domain-Driven Design. It’s a way of designing software by focusing on the business domain — the real-world problem the …