Java Multithreading & Concurrency — Overview

Concurrency is a core concept in Java and a favorite interview topic. It allows applications to execute multiple tasks simultaneously, improving performance, scalability, and responsiveness. However, it also introduces challenges like race conditions, deadlocks, and thread safety.

This overview lays the foundation for mastering Java’s concurrency model, preparing you for both interviews and real-world system design.

Introduction

• Multithreading: Running multiple threads (lightweight processes) within a single program.
• Concurrency: Ability of a program to deal with multiple tasks at once (may or may not be parallel).

Multithreading is one way to achieve concurrency, but concurrency can also come from async I/O, event-driven models, or distributed systems.